Stereotactic Body Radiotherapy (SBRT) for Breast Cancer Spinal Metastases is Associated with Low Rates of Long-Term Local Failure (LF) and Vertebral Compression Fracture (VCF) Independent of Molecular Status

PURPOSE/OBJECTIVE(S)

There is limited outcome data specific to breast cancer spinal metastases following spine SBRT. This study aims to report outcomes specific to breast cancer spinal metastases receiving spine SBRT and determine the implication of biomarker status.

MATERIALS/METHODS

We have been maintaining a prospective database since the inception of the spine SBRT program. A retrospective review identified 168 breast cancer patients with 409 spinal segments treated with spine SBRT between January 2008 and January 2023. Molecular subtypes were grouped based on luminal A, luminal B, basal, and HER2 enriched. Patients were followed with q3-monthly full-spine MRI and a clinical assessment. The primary endpoint was MRI-based local failure (LF), and secondary endpoints were overall survival (OS) and vertebral compression fracture (VCF).

RESULTS

The median follow-up was 33 months (range, 3.3-123 months). Amongst the 168 patients, the majority were ECOG 0 or 1 (95%), neurologically intact (94%), polymetastatic (74%), and either luminal A (71%) or luminal B (8%). A total of 17% of patients were HER2+ve versus 83% HER2-ve. Of 409 treated segments the majority (76%) had no prior radiation or surgery (de novo), were SINS stable (60%), had either no or low-grade epidural disease (86%) and treated with 24-28 Gy in 2 fractions (73%). The LF and OS rates at 1, 3, and 5 years were 5%, 11%, and 14%, respectively, and 91%, 65%, and 45%, respectively, independent of molecular subtype on univariate analyses. The cumulative risk of VCF at 2 and 5 years was 7% and 10%, respectively.

CONCLUSION

We observe, in the largest breast cancer spine cohort to date, excellent long-term local control rates independent of molecular sub-group, and acceptable VCF rates.

Outcomes Specific to Spinal Metastases with Paraspinal Disease Extension Following Spine Stereotactic Body Radiotherapy

PURPOSE/OBJECTIVE(S)

Spinal metastases with paraspinal disease (PD) extension are known to have worse outcomes following stereotactic body radiotherapy (SBRT). Characteristics of the PD itself have not been investigated to determine the impact on outcomes such as local control, which is the purpose of this study.

MATERIALS/METHODS

We retrospectively reviewed those patients who had SBRT for spinal metastases with PD disease, identified from a prospectively maintained database. Spinal metastases previously irradiated or surgical resected were excluded. The extent of PD was classified as involving the rib, neuroforamina, and muscle invasion. The gross tumor volume of PD (GTV_PD) and the clinical target volume of PD (CTV_PD) were segregated from the bony compartments based on the treatment plan contours. The outcomes of interest included the cumulative risk of local failure (LF), re-irradiation rates (ReRT), and overall survival (OS). LF and ReRT were estimated for each treated sites using the competing risk model (death as the competing risk), while OS was evaluated per patient using the Kaplan Meier method.

RESULTS

A total of 86 patients with 96 spinal metastases sites with PD were included. Of the 96 treated sites, 65% (62/96), 29% (28/96) and 6% (6/96) of PD spanned 1, 2, and 3 vertebral levels respectively. The median follow-up was 12.4months (range: 0.6-100months). The 6- and 12-month OS for the cohort was 81% and 51%, respectively. 33/86 (38%) patients had radioresistant cancer (gastrointestinal, renal cell carcinoma, thyroid, sarcoma, or melanoma). Involvement of rib, neuroforamina and muscle invasion were observed in 39% (37/96), 65% (62/96) and 21% (20/96) of the treated sites, respectively. Epidural disease was present in 57% (55/96) of treated sites. The median GTV_PD volume was 7cc (range: 0.3-114cc), and the median CTV_PD volume was 24cc (range: 0.4-248cc). The prescribed doses were 24 Gy/2 fractions (fx) (80%), 28 Gy/2 fx (10%) and 30 Gy/4 fx (10%). There were 84 treated sites with at least one post-treatment MRI available for LF assessment. The crude LF risk was 32% (27/84), and the 6- and 12-month cumulative LF rates were 12% and 28%, respectively. There was a trend towards an increased risk of LF when PD involved the rib (35% vs 24% at 1 year respectively, P = 0.07) and muscle (67% vs 20% at 1 year respectively; P = 0.06), but no difference in LF for neuroforamina involvement (26% vs 34% at 1 year respectively, P = 0.5). There were no differences in LF based on cancer radioresistance (P = 0.6), GTV_PD volume (P = 0.3) or CTV_PD volume (P = 0.4). Of the 96 treated sites, 14% (14/96) were re-irradiated (9 with repeat SBRT and 5 with conventional EBRT) at a median of 15 months (range: 4.7-59 months) post initial SBRT. The cumulative incidence of ReRT at 6- and 12-months were 1.2% and 7.3%, respectively.

CONCLUSION

PD involving adjacent rib and muscle may be associated with worse LF following SBRT. Further expansion of the cohort and dosimetric analyses are ongoing.

Stereotactic Body Radiotherapy for Posterior Element Only Spinal Metastases: Outcomes and Validation of Recommended Clinical Target Volume Delineation Practice

PURPOSE/OBJECTIVE(S)

Spine stereotactic body radiotherapy (SBRT) results in improved local control and pain response compared to conventional external beam radiotherapy. Consensus stipulates MRI-based delineation of the clinical target volume (CTV) is critical and is based on spine segment sector involvement. The applicability of these contouring guidelines to metastases confined to the posterior elements is unknown. The purpose of this study was to determine the patterns of failure, as well as the safety of treating posterior element metastases when the vertebral body was intentionally excluded from the CTV.

MATERIALS/METHODS

A retrospective review of a prospectively maintained database of 605 patients and 1412 spine segments treated with spine SBRT was performed. Only treated segments involving the posterior elements alone were included for the analyses. The primary outcome was local failure, as per SPINO recommendations, and secondary outcomes included patterns of failure, toxicities. Clinical and tumor factors were reported with descriptive statistics. The cumulative risk of local failure was estimated using the Fine-Gray method, accounting for death before local failure as a competing risk.

RESULTS

A total of 24/605 patients and 31/1412 segments within the database were treated to the posterior elements only. Local failure occurred in 11/31 segments. The cumulative rate of local recurrence was 9.7% at 12 months and 30.8% at 24 months. Amongst local failures, the most common histologies were renal cell carcinoma (36.4%) and non-small cell lung cancer (36.4%). At baseline, 4/11 (36.4%) segments with local failure (36.4%) had epidural disease and 8/11 (72.7%) had paraspinal disease. Most local failures were treated in the de novo setting (8/11, 72.7%). 6/11 (54.5%) failed exclusively within treated CTV sectors and 5/11 (45.5%) with both treated and adjacent untreated sectors. Of these five, four had disease progression within the untreated vertebral body. No failures occurred exclusively within the untreated vertebral body. One patient (4.2%) experienced a grade 4 skin toxicity and one patient (4.2%) developed an iatrogenic Grade 1 vertebral compression fracture.

CONCLUSION

Posterior element alone metastases are rare. Our analyses support SBRT consensus contouring guidelines such that the vertebral body can be excluded from CTV in spinal metastases confined to the posterior elements.

Outcomes Following Dose Escalated Radiotherapy for High Grade Meningioma

PURPOSE/OBJECTIVE(S)

Conventionally fractionated radiotherapy (RT) is a defined treatment following surgery for atypical and malignant meningioma. However, the optimal radiotherapeutic approach is not well defined. We present the results of our dose-escalation strategy.

MATERIALS/METHODS

Consecutive patients with a histopathologic grade 2 or 3 meningioma treated with RT were retrospectively reviewed. The primary outcome was progression-free survival (PFS), and secondary outcomes included cause-specific survival (CSS), overall survival (OS), local failure and incidence of radiation necrosis. We specifically compared the dose-escalation cohort, defined as those treated with ≥66 Gy EQD2 (equivalent dose in 2 Gy fractions, a/b = 10), to the standard dose cohort receiving <66 Gy EQD2. We defined adjuvant as RT delivered within 6 months of surgery otherwise the treatment was salvage.

RESULTS

A total of 118 patients with Grade 2 (111/118) or 3 (7/118) meningioma were identified. 54/118 (45.8%) received dose-escalation and 64/118 (54.2%) standard dosing. 34/54 (63.0%) dose-escalated and 45/64 (70.3%) standardly dosed were treated adjuvantly. The median follow-up was 45.4 months (IQR: 24.0-80.0 months) and median OS was 9.7 years. Post-operative residual disease was present in all dose-escalated patients, as compared to 65.6% in the standard dose cohort. PFS at 3-, 4- and 5-years in the dose-escalated vs. standard dose cohort were 78.9%, 72.2% and 64.6% vs. 57.2%, 49.1% and 40.8%, respectively, (p = 0.030). On multivariable (MVA) analysis, dose-escalation (HR: 0.544, 95% CI: 0.303-0.977, p = 0.042) was associated with improved PFS, whereas ≥2 surgeries (HR: 1.989, 95% CI: 1.049-3.773, p = 0.035) and older age (HR: 1.035, 95% CI:1.015-1.056, p<0.001) associated with worse PFS. The cumulative risk of local failure at 3-, 4- and 5-years in the dose-escalated vs. standard dose cohort were 16.9%, 23.8% and 31.8% vs. 39.6%, 45.6% and 53.9%, respectively, favoring dose-escalation (p = 0.016). MVA confirmed dose-escalation as predictive of a lower risk of LF (HR: 0.483, 95% CI: 0.263-0.887, p = 0.019), while ≥2 surgeries prior to RT predicted for greater LF rates (HR:2.145, 95% CI:1.220-3.771, p = 0.008). A trend was observed for prolonged CSS and OS in the dose escalation cohort (p = <0.1). Seven patients (5.9%) developed symptomatic radiation necrosis (RN) with no significant difference between the two cohorts.

CONCLUSION

Dose-escalated radiotherapy for high grade meningioma to at least 66 Gy is associated with significantly improved rates of local control and PFS with an acceptable risk of RN.

Staged Stereotactic Radiosurgery as a Novel Adaptive Approach to Salvage Previously Irradiated Brain Metastases

PURPOSE/OBJECTIVE(S)

We report outcomes specific to a novel 3 fraction (frx) staged stereotactic radiosurgery (St-SRS) regimen designed to salvage metastases previously irradiated and considered to be at high risk of radiation necrosis (RN).

MATERIALS/METHODS

A total of 24 patients with 55 metastases treated with our 3 frx St-SRS approach were reviewed. Prior to each frx, patients were re-simulated and planned with a new MRI to allow for treatment adaption. The primary endpoint was the cumulative incidence of local failure (LF) and secondary endpoints included tumor dynamics and RN rates.

RESULTS

The median follow up was 9.0 months (range: 2.7-40.1 months) and median age was 59-years (range: 32-84). Primary cancers were of breast (44%), lung (33%), melanoma (22%), and gastro-intestinal (1%) origin. Individual metastases treated with St-SRS had initially failed surgery and post-op cavity hypofractionated SRS (HSRS) for 2/55 (4%), SRS alone for 19/55 (34%), whole brain radiation (WBRT) alone for 6/55 (11%), HSRS for 2/55 (4%), and prior SRS and WBRT exposure for 28/55 (51%). 46/55 (84%) were prescribed 8 Gy, 8 Gy, 4 Gy; 8/55 (14%) had 6 Gy, 6 Gy, 4 Gy and 1/55 (2%) had 8 Gy, 8 Gy, 6 Gy. The median number of weeks between frx was 2.6 (range: 1.0-6.8). The median of the mean and maximum target doses were 9.7 Gy (range: 5.4-11.7 Gy) and 12.4 Gy (range, 7.5-16.0 Gy) respectively. The median prescription isodose line was 62% (range: 50-85%). The mean lesion volume and diameter was 3.8cc (range: 0.05-24.8cc) and 1.6cm (range: 0.2-4.4cm), respectively. The mean percent target volume coverage, Paddick Conformality Index and Gradient Index were 100% (range: 97-100%), 0.7 (range: 0.1-0.9), and 3.2 (range: 2.5-6.7), respectively. The mean volume change between staged frxs was -4.2% (range: -69.3 to +63.1%), and based on the first and last St-SRS MRI was -10.8% (range: -86.6% to +68.7%). The crude LF rate was 27%. The median time to LF was 3.4 months (range: 1.2-7.4 months). Amongst those with a LF, 7/15 (46%) were melanoma, 6/15 (40%) HER2 positive breast cancer, 1/15 (7%) gastrointestinal and 1/15 (7%) non-small cell lung carcinoma. 8/15 (53%) had prior WBRT and SRS exposure, 1/16 (7%) surgery and cavity HSRS, 5/15 (33%) SRS alone and 1/15 (7%) WBRT alone. Only asymptomatic RN events were observed in 4/55 (7%).

CONCLUSION

St-SRS is a promising approach to salvage previously irradiated brain metastases, including prior SRS, with a favorable rate of RN. Tumor volume dynamics between stages can be significant warranting adaptive replanning.

Multi-Institutional Validation of the Recursive Partitioning Analysis for Overall Survival in Patients Undergoing Spine Radiosurgery for Spine Metastasis

PURPOSE/OBJECTIVE(S)

The recently published spine radiosurgery (sSRS) recursive partitioning analysis (RPA) for overall survival (OS) separated patients into 3 distinct prognostic groups. We sought to externally validate this RPA using 3 separate multi-institutional datasets.

MATERIALS/METHODS

A total of 444 patients were utilized to develop the recently published sSRS RPA predictive of OS in patients with spine metastases. The RPA identified three distinct prognostic classes. RPA Class 1 was defined as KPS >70 and controlled systemic disease (n = 142); RPA Class 2 was defined as KPS>70 with uncontrolled systemic disease or KPS ≤70, age ≥54 and absence of visceral metastases (n = 207); RPA Class 3 was defined as KPS ≤70 and age <54 years or KPS≤70, age ≥54 years and presence of visceral metastases (n = 95). We utilized data from 3 large tertiary care centers to independently validate this RPA. Data from each institution was utilized independently to validate the RPA to minimize confounding based on institutional differences in patient selection. A total of 1,184 patients (221 patients from institution A, 749 institution B, and 214 from institution C) were in the validation cohort and were divided based on their RPA Class. Kaplan-Meier method was used to estimate OS and log-rank test was used to compare OS between RPA classes.

RESULTS

In each of the validation cohorts, the median OS was 19.9 months (institution A), 11.0 months (institution B), and 24.4 months (institution C). The patient distribution into RPA classification based on Institution A/B/C was, Class 1 (19.4%, 15.1%, 50.5%), Class 2 (74.7%, 57.7%%, 37.9%), and Class 3 (5.9%, 27.2%%, 11.2%), respectively. The median OS for patients in the validation cohort at Institution A/B/C based on RPA class was Class 1 (54 months, 27.1 months, 50.0 months), Class 2 (15.9 months, 13.0 months, 15.1 months) and Class 3 (6.9 months, 3.5 months, 6.1 months), respectively. Patients in RPA Class 1 had a significantly better OS compared to those in Class 2 of the each of the three external institution validation cohorts (p<0.01). Similarly, patients in RPA Class 2 had a significantly better OS compared to those in Class 3 (p<0.01).

CONCLUSION

The external datasets from three large institutions independently validated the spine SRS RPA successfully for OS in patients undergoing sSRS for spinal metastases. This is the first RPA for OS to have been externally validated using multiple large datasets. Based on this validation, upfront spine SRS is strongly supported for patients in RPA Class 1 and Class 2 and is also cost effective with median OS >11 months for these patients. Patients in RPA Class 3 would benefit most from upfront conventional radiotherapy given their poor expected survival. Given successful external validation, this RPA helps guide physicians to identify those patients with spinal metastases who most benefit from sSRS.

Molecular Status Predicts for Local Control in Patients with Non-Small Cell Lung Cancer Spinal Metastases Following Spine Stereotactic Body Radiotherapy

PURPOSE/OBJECTIVE(S)

We report outcomes after spine stereotactic body radiotherapy (SBRT) in patients with metastatic non-small cell lung cancer (NSCLC), to determine the significance of programmed death-ligand 1 (PD-L1) status and epidermal growth factor (EGFR) mutation on local failure (LF) rate.

MATERIALS/METHODS

A total of 165 patients and 389 spinal segments were retrospectively reviewed from 2009 to 2021. Baseline patient characteristics, treatment and outcomes were abstracted. Primary endpoint was LF and secondary outcomes included overall survival (OS) and vertebral compression fracture (VCF) rates. OS was estimated using the Kaplan-Meier method. Cumulative LF and VCF rates were calculated using competing risk analysis method. Multivariable analysis (MVA) evaluated factors predictive of LF and VCF.

RESULTS

Median follow-up was 13 months (range, 0.5-95 months). Median OS was 18.4 months (95% CI 11.4-24.6). Median age was 67 years (range, 28.2-89.9). 52% were female, 76% had an adenocarcinoma histology and 61% had a smoking history. 49/165 (29%) had an EGFR mutation. PD-L1 status was analyzed in 109/165 (66%) patients with 16% PD-L1 ≥ 50%, 20% PD-L1 1-49% and 35% PD-L1 <1%. Of 389 segments, 79% were de novo and 21% were previously radiated. At baseline, 35% had a VCF, 27% had epidural disease, 27% had paraspinal extension, and 49% were Spinal Instability in Neoplasia Score (SINS) stable. 239/389 (61%) were treated with either 24 or 28 Gy in 2 SBRT fractions. Within 1 month of SBRT, 39/165 (24%) had a tyrosine kinase inhibitor, 27/165 (16%) immunotherapy (IO) with or without chemotherapy, and 31/165 (19%) chemotherapy alone. LF cumulative incidence at 1- and 2-years was 16.3% (95% CI 12.8-20.3%) and 25.4% (95% CI 20.9%-30%), respectively. EGFR positivity (p<0.0001), PD-L1≥50% (p = 0.013) and treatment with IO within 1 month of SBRT (p = 0.004) predicted for improved local control on MVA. The 1- and 2-year LF rate in EGFR-positive vs. negative patients were 12.9% vs. 16.6% and 17.7% vs. 28.8%, respectively, and in those PD-L1 ≥50% vs PD-L1<50% were 7.8% vs. 19.6% and 7.8% vs. 38.1% respectively. Cumulative incidence of VCF at 1- and 2-years were 6.6% (95% CI 4.4-9.4%) and 8.8% (95% CI 6.1-12.0%). MVA identified prior SBRT to the same treated segment (P<0.0001) and a baseline VCF (p<0.0001) as significant predictors. 18/389 (4.6%) had radiation-induced radiculopathy and no radiation myelopathy events detected.

CONCLUSION

We identify the predictive utility of EGFR mutation and PD-L1 ≥50% status on local control in NSCLC patients with spinal metastases treated with spine SBRT, and a therapeutic benefit with peri-SBRT IO.

Predictors of Tumor Dynamics during a 6-Week Course of Chemoradiotherapy for Glioblastoma

PURPOSE/OBJECTIVE(S)

Our prior imaging studies have shown geometrically meaningful inter-fraction tumor dynamics specific to glioblastoma (GBM). We aim to identify predictors associated with tumor dynamics during a 6-week course of concurrent chemoradiotherapy (CRT) for GBM.

MATERIALS/METHODS

Patients enrolled in a prospective serial magnetic resonance imaging (MRI) study were reviewed. All patients were treated with 54-60 Gy in 30 fractions. The gross tumor volume (GTV) included the surgical cavity and T1c enhanced residual tumor; clinical tumor volume (CTV) included GTV with a 15mm isotropic expansion, respecting anatomical boundaries; planning target volume (PTV) was 4mm expansion. MRIs were obtained at RT planning (F0), fraction 10 (F10), and fraction 20 (F20). Tumor dynamic metrics (relative to F0) assessed included the GTV volume (Vrel), Hausdorff distance (dH) and migration distance (dM). dH is the average distance between two datasets in metric space. dM is the maximum linear displacement of the GTV in any direction. Factors to be determined associated with tumor dynamics included: age, sex, corpus callosum (CC) involvement, extent of surgery (gross total resection (GTR), subtotal resection (STR) or biopsy alone (Bx)), MGMT methylation and IDH mutation status.

RESULTS

A total of 129 patients were reviewed. Median GTV was 20.9cc at F0, 17.6cc at F10 (Vrel 0.85), and 16.1cc at F20 (Vrel 0.78). Patients without CC involvement had more marked GTV volume reduction: Vrel 0.82 vs 1.02 with CC involvement at F10 (P = 0.05), and Vrel 0.77 vs 0.88 with CC involvement at F20 (P = 0.03). Patients with GTR (vs STR vs Bx) had more marked GTV volume reduction across all time points: Vrel 0.78, 0.85 and 1.07 respectively at F10 (P = 0.001), and Vrel 0.69, 0.80, 1.04 respectively at F20 (P = 0.001). The median dH was 8.1mm at F10 and 9.2mm at F20. Patients with CC involvement (vs without CC involvement) had a larger dH: 54% vs 25% had dH>10mm respectively at F10 (P = 0.03), and 73% vs 28% had dH>10mm respectively at F20 (P<0.005). Patients with a GTR had smaller dH at both F10 (P = 0.02) and F20 (P = 0.006). At F20, 20%, 47% and 37% of patients with GTR, STR and Bx had dH>10mm (P = 0.04). The median dM were 4.7mm at F10 and 4.7mm at F20. Patients with CC involvement (vs without CC involvement) had larger dM: 41% vs 12% had dM >10mm respectively at F10 (P = 0.01), and 45% vs 9% had dM >10mm respectively at F20 (P<0.001). Patients with GTR had smaller dM at F10 (P = 0.03) and F20 (P0.002). At F20, 0%, 25% and 19% of patients with GTR, STR and Bx had dM>10mm (P = 0.002). Age, sex, MGMT methylation and IDH mutation status were not associated with Vrel, dH and dM at F10 and F20.

CONCLUSION

We identified CC involvement and extent of surgery to be associated with tumor dynamics at F10 and F20 over the course of CRT for GBM. This offers opportunities to better select patients who may benefit from earlier/ more frequent RT replan/ adaptation to ensure adequate tumor coverage, or to reduce RT toxicities.

Stereotactic Body Radiotherapy (SBRT) for Sacral Metastases: Deviation from Recommended Target Volume Delineation Predicts Higher Risk of Local Failure

PURPOSE/OBJECTIVE(S)

A international consensus recommendation was published to guide target volume delineation specific to sacral stereotactic body radiotherapy (SBRT). We report outcomes after sacrum SBRT, focusing on the impact of contouring deviation on local failure (LF) risk, with an aim to validate this guideline.

MATERIALS/METHODS

All patients who underwent SBRT to any level between S1 and S5 from 2010 to 2021 were identified from a prospectively maintained institutional database. The primary outcome was magnetic resonance-based LF. Secondary outcomes included vertebral compression fracture (VCF) and overall survival (OS). Cumulative LF and VCF rates were calculated per segment using the competing risk analysis method. Kaplan Meier analysis was used to estimate OS per patient. Cox proportional hazards model was used to assess predictive factors of LF, VCF, and OS.

RESULTS

A total of 215 treated sacral segments in 112 patients were retrospectively reviewed. The median follow-up was 13 months (range, 0.4-116.9). The median age was 64 years (range, 18-86), and 56% were male. Most patients (52%) had treatment to a single segment. The median clinical target volume (CTV) was 129.2 cc (range, 5.8-753.5). Most segments were treated with 30 Gy/4 fractions (51%), 24 Gy/2 fractions (31%), or 30 Gy/5 fractions (10%). Thirty-one percent of segments were of radioresistant histology (gastrointestinal, kidney, melanoma, sarcoma, or thyroid primary), and 51% had extraosseous disease. Sixteen percent of segments were under-contoured per consensus guidelines, with incomplete coverage of the involved sector (71%), omission of the adjacent uninvolved sector (17%), or both (11%) as the causes for deviation. The cumulative incidence of LF was 18.4% (95% CI 13.5-24.0) at 12-months and 23.1% (95% CI 17.6-29.0) at 24-months. On multivariate analysis (MVA), under-contouring (HR 2.4, 95% CI 1.3-4.7, p = 0.008), radioresistant histology (HR 2.4, 95% CI 1,4-4.1, p = 0.001), and extraosseous extension (HR 2.5, 95% CI 1.3-4.7, p = 0.005) were predictors of increased risk of LF. The LF rates at 12/24-months were 15.1%/18.8% for segments contoured per guideline versus 31.4%/40.0% for those under-contoured. The cumulative incidence of VCF was 7.1% (95% CI 4.1-11.1) at 12-months and 12.3% (95% CI 8.2-17.2) at 24-months. On MVA, female gender was the only risk factor for VCF (HR 2.3, 95% CI 1.1-5.2, p = 0.04). The median OS was 29.5 months (95% CI 17.5-59.2). On MVA, primary kidney (HR 4.7, 95% CI 1.7-12.5, p = 0.002) or lung histology (HR 3.4, 95% CI 1.3-8.5, p = 0.010), the presence of liver (HR 2.8, 95% CI 1.2-6.4, p = 0.016) or lung (HR 2.5, 95% CI 1.3-5.1, p = 0.008) metastases, ECOG performance status 2 or 3 (HR 3.3, 95% CI 1.2-8.2, p = 0.013), and the presence of sensory or motor deficit (HR 2.6, 95% CI 1.2-5.4, p = 0.012) were prognostic for worse OS.

CONCLUSION

Sacral SBRT is associated with high rates of efficacy and an acceptable VCF risk. Adherence to target volume delineation consensus guidelines reduces the risk of LF.

Dosimetric Implications of Weekly On-Line MR-Guided Adaptive Radiotherapy (RT) for Glioblastomas (GBM) Growing during RT

PURPOSE/OBJECTIVE(S)

The UNITED trial (NCT04726397) involves once-weekly on-line adaptive RT for patients with GBM on a 1.5T MRI-Linac (MRL). For tumors that continue to enlarge during the course of RT, we hypothesize that the adaptive strategy improves the dosimetric coverage of the target relative to a non-adaptive strategy.

MATERIALS/METHODS

As per the trial protocol, T1+contrast (T1c) and FLAIR MRI sequences were acquired once per week during RT to re-define and adapt the gross tumor volume (GTV) as the contrast enhanced volume, the clinical target volume (CTV) as a 5mm expansion around the GTV plus adjacent FLAIR hyperintense regions considered at-risk by the radiation oncologist, and a 3 mm PTV around the CTV. Nine UNITED patients with tumors that grew throughout RT (GTV and/or CTV) were identified. 5/9 patients were treated with 60 Gy in 30 fractions (6 weekly adaptions) and 4/9 with 40 Gy in 15 fractions (3 weekly adaptions). For the final week's GTV and CTV (GTVfinal and CTVfinal), the dosimetric outcomes of the delivered and adaptive summative plans (Dsum) were compared to dose of the baseline plan (Dbaseline) generated on Fraction 1 of treatment, the latter being indicative of the theoretical situation where no further adaption was taken. We measured the dose to 99% of the GTVfinal and CTVfinal: Dsum99 and Dbaseline99.

RESULTS

For each adaptive fraction, the plan was optimized to achieve an objective of D99 greater than 95% of the prescription (D99>95%) for both the GTV and CTV. The relative increase in GTVfinal and CTVfinal from baseline was on average 119% (range: 98% to 144.7%) and 128% (range: 109% to 176%), respectively. The proportion of CTVfinal that was outside the baseline plan's PTV was on average 11.5% (range: 0% to 32%). The GTVfinal did not extend beyond the baseline PTV for any of the 9 cases. GTVfinal Dsum99 was >95% for all cases while CTVfinal Dsum99 was < 95% in 2 of 9 cases (74%, and 87%). By contrast, the baseline plan, if given for all fractions with no further adaptation, yielded a D99 for CTVfinal of <95% in 5 of 9 cases (28%, 52%, 75%, 84%, and 87%). In general, coverage of the CTVfinal decreased with increasing levels of CTVfinal outside of the baseline PTV. For all 5 cases where CTVfinal D99<95% on the baseline plan, more than 10% of CTVfinal was outside of the baseline PTV. Small margin, weekly adaptive RT on an MRL for GBM maintains coverage of the GTV in the presence of tumor growth while minimizing the degree of normal brain tissue irradiated. Dosimetric impact on non-GTV/CTV brain is outside the scope of the present study.

CONCLUSION

Preliminary results indicate that a once weekly adaptive approach for small margin MR-guided RT improves tumor coverage for progressive tumors compared to a static (baseline) plan without adaptation.

Dosimetric Parameters Predictive of Treatment-Related Toxicity in High Dose-Rate Brachytherapy as Monotherapy for Prostate Cancer

PURPOSE/OBJECTIVE(S)

High dose-rate (HDR) brachytherapy as monotherapy is an effective treatment for patients with low- and intermediate-risk prostate cancer and is increasingly being offered as a 2-fraction protocol. There is a lack of consensus on the optimal dosimetric planning parameters to use, or whether there is any benefit summating dosimetric parameters from more than one implant. Our goal is to determine planning parameters associated with disease control, toxicity and health-related quality of life (HRQOL).

MATERIALS/METHODS

Data were collected on 83 patients with low- and intermediate-risk prostate cancer who received 2 fractions of 13.5 Gy HDR brachytherapy without androgen-deprivation therapy as part of a randomized phase II clinical trial. An in-house deformable, registration algorithm was used to co-register and dose-summate the plans from both implants for each patient. Acute and late GU and GI toxicities were measured using CTCAE 4.0 and HRQOL was measured in urinary, bowel, sexual and hormonal domains using the EPIC scores. Treatment efficacy was assessed through PSA measurement and imaging with or without biopsy where indicated. Covariates included baseline clinical factors, disease characteristics and treatment dosimetric parameters. Cox proportional hazards was performed to evaluate covariates impact on treatment toxicity and efficacy, and logistic regression analysis evaluated covariates impact on HRQOL.

RESULTS

Among the 83 patients, median prostate volume was 46.7cm3. Median summated planning target volume receiving 100% prescription dose (PTV V100%) was 97.4%, median PTV V150% 42.4% and median PTV V200% 15.5%. Median highest dose to the 1cm3 rectum (D1cc) was 66.9% of the prescription dose and median rectum V80% was 0.008cm3. Median urethral D1cc was 99.0% of the prescription dose, median urethral Dmax 121.7% and median urethral D10% 116.2%. Grade ≥2 GI toxicity was uncommon (3.7% acute and 8.5% late), but grade ≥2 GU toxicity was reported in 73.2% (acute) and 46.3% (late) patients. Rectum D1cc and V80% were found to be significantly associated with grade 2 or higher acute GI toxicity, while use of a-blocker at baseline was associated with grade ≥2 acute GU toxicity. Similarly, use of a-blocker was associated with late grade ≥2 GU toxicity, but with no dosimetric associations. No other variables were associated with treatment-related toxicities. Only rectum D1cc was significantly associated with changes in bowel EPIC scores. Estimated 5-year biochemical disease-free survival was 93.9% and 5-year cumulative incidence of local failure was 3.8%.

CONCLUSION

HDR monotherapy with 27 Gy delivered in 2 fractions in treatment of prostate cancer is well tolerated with high rates of disease control and minimal toxicity. Dose summation between 2 fractions of HDR brachytherapy is feasible, with rectal dose predicting acute GI toxicity. The lack of association between dose metrics and urinary toxicity raises the potential for further dose escalation.

Dosimetric Predictors of Toxicities and Quality of Life Following Two-Fraction Stereotactic Body Radiotherapy for Prostate Cancer

PURPOSE/OBJECTIVE(S)

There is emerging interest in two-fraction stereotactic body radiotherapy (2#SBRT) for localized prostate cancer. However, there is limited data to guide organs at risk (OAR) dose constraints in 2#SBRT. We aim to identify dosimetric predictors of toxicities and quality of life (QoL) using real life patient data from two prospective 2#SBRT trials.

MATERIALS/METHODS

We included 60 patients who had 2#SBRT in the 2STAR (NCT02031328) and 2SMART (NCT03588819) phase 2 trials. The prescribed dose was 26Gy to the prostate +/- focal boost of 32Gy to the dominant intraprostatic lesions. Toxicities and QoL data were prospectively collected using CTCAEv4 and EPIC26 questionnaires. For QoL, we reported the minimal clinical important changes (MCIC), defined as changes in QoL score of >0.5 standard deviation from baseline QoL score. We evaluated the bladder, urethra, rectum, and penile bulb dosimetry (urethra dosimetry only available in 30 patients in 2SMART trial). Some of the dosimetric parameters were log-transformed to normalize the distribution. Cox regression was used to identify dosimetric predictors for acute and late grade ≥2 GU toxicities. Logistic regression was used to identify dosimetric predictors for late MCIC in urinary, bowel and sexual QoL domains. Backward stepwise selection was used to identify significant dosimetric parameters. For GU toxicities and urinary QoL, three additional clinical factors (age, prostate volume and IPSS) were included in the final model as confounding factors. Receiver operating characteristics curve was used to identify cut-off for significant dosimetric parameters.

RESULTS

The median follow-up for the cohort was 56 months (range: 39-78 months). The cumulative acute and late grade ³2 GU toxicities were 62% (37/60) and 57% (34/60) respectively. No bladder or urethra dosimetric parameter was associated with acute grade ≥2 GU toxicities. Bladder D0.5cc was significant predictor of late grade ≥2 GU toxicities in univariate model (P = 0.05), but not in multivariate model. Baseline IPSS score was the single strongest predictor for late grade ≥2 GU toxicities (HR = 1.9; 95% CI = 1.1-3.4; P = 0.03). For late QoL outcomes, there were 36% (21/58), 28% (16/58), and 29% (17/58) of patients with MCIC in urinary, bowel and sexual QoL domains respectively. Bladder V10Gy was associated with late urinary MCIC in multivariate model after adjusting for clinical confounders (HR = 2.6, 95% CI = 1.1-6.6; P = 0.04). 48% (14/29) and 24% (7/29) of patients with bladder V10Gy>13.9% and V10Gy≤13.9% respectively had late urinary MCIC. No rectum and penile bulb dosimetry parameters was identified to be associated with late bowel or sexual QoL.

CONCLUSION

Using real life patient data from prospective clinical trials with medium term follow-up, we identified statistically significant bladder dosimetry parameter predictive of late urinary QoL. This finding could be useful to guide OAR dose constraints in prostate 2#SBRT trials.

Association of Serious Hypoglycemic Events in Older Adults With Changes in Glycemic Performance Measures

BACKGROUND

Reducing serious hypoglycemic events is a Federal-wide objective. Despite studies of trends for rates of serious hypoglycemia in existing literature, rigorous evaluation of links between the observed trends and changes in professional guidelines or performance measures for glycemic control is lacking.

OBJECTIVE

To evaluate whether changes in professional society guidelines and performance measures for glycemic control correspond to changes in rates of serous hypoglycemia.

RESEARCH DESIGN

This was a retrospective observational study. We merged Veterans Health Administration (VHA) and Medicare patient-level databases of VHA patients and identified those aged 65 years and above and receiving hypoglycemic agents. We derived age-adjusted and sex-adjusted annual rates and constructed piecewise Poisson regression models adjusting for age and sex to assess time trends of the rates.

SUBJECTS

VHA patients, 2002-2015.

MEASURES

The main outcome was the annual rates (2004-2015) of serious hypoglycemia, defined as hypoglycemia-related emergency department visits or hospitalizations. Secondary outcomes were annual rates of hemoglobin (Hb) A1c level <7% and >9%. Age and sex were additional variables.

RESULTS

The annual rate for hypoglycemia decreased by 4.8% (rate ratio: 0.952; 95% confidence interval, 0.949-0.956) for 2008-2015 but did not change (1.001; 0.994-1.001) in 2004-2008. In 2008-2015, the annual rate for HbA1c <7% decreased by 5.0% (0.950; 0.949-0.951) but for HbA1c >9%, increased by 7.9% (1.079; 1.076-1.082).

CONCLUSION

The cooccurrence of decreasing rates for HbA1c<7% and serious hypoglycemia since 2008 supports the possibility that withdrawal of a <7% HbA1c measure in 2008 impacted clinical practice and patient outcomes.

Risk of clinically relevant hyperglycemia with metoprolol compared to carvedilol in older adults with heart failure and diabetes

BACKGROUND

Although prior literature suggests that metoprolol may worsen glucose control compared to carvedilol, whether this has clinical relevance among older adults with diabetes and heart failure (HF) remains an open question.

METHODS

This was a US retrospective cohort study utilizing data sourced from a 50% national sample of Medicare fee-for-service claims of patients with part D prescription drug coverage (2007-2017). Among patients with diabetes and HF, we identified initiators of metoprolol or carvedilol, which were 1:1 propensity score matched on >90 variables. The primary outcome was initiation of a new oral or injectable antidiabetic medication (proxy for uncontrolled diabetes); secondary outcomes included initiation of insulin and severe hyperglycemic event (composite of emergency room visits or hospitalizations related to hyperglycemia).

RESULTS

Among 24 239 propensity score-matched pairs (mean [SD] age 77.7 [8.0] years; male [39.1%]), there were 8150 (incidence rate per 100 person-years [IR] = 33.5) episodes of antidiabetic medication initiation among metoprolol users (exposure arm) compared to 8576 (IR = 33.4) among carvedilol users (comparator arm) compared to corresponding to an adjusted hazard ratio (aHR) of 0.97 (95% confidence interval [CI]: 0.94, 1.01). Similarly, metoprolol was not associated with a significant increase in the risk of secondary outcomes including insulin initiation: aHR of 0.98 (95% CI: 0.93, 1.04) and severe hyperglycemic events: aHR of 0.98 (95% CI: 0.93, 1.02).

CONCLUSIONS

In this large study of older adults with HF and diabetes, initiation of metoprolol compared to carvedilol was not associated with an increase in the risk of clinically relevant hyperglycemia.

How patients interpret early signs of foot problems and reasons for delays in care: Findings from interviews with patients who have undergone toe amputations

Aims

To describe how patients respond to early signs of foot problems and the factors that result in delays in care.

Methods

Semi-structured interviews were conducted with a large sample of Veterans from across the United States with diabetes mellitus who had undergone a toe amputation. Data were analyzed using inductive content analysis.

Results

We interviewed 61 male patients. Mean age was 66 years, 41% were married, and 37% had a high school education or less. The patient-level factors related to delayed care included: 1) not knowing something was wrong, 2) misinterpreting symptoms, 3) “sudden” and “unexpected” illness progression, and 4) competing priorities getting in the way of care-seeking. The system-level factors included: 5) asking patients to watch it, 6) difficulty getting the right type of care when needed, and 7) distance to care and other transportation barriers.

Conclusion

A confluence of patient factors (e.g., not examining their feet regularly or thoroughly and/or not acting quickly when they noticed something was wrong) and system factors (e.g., absence of a mechanism to support patient’s appraisal of symptoms, lack of access to timely and convenient-located appointments) delayed care. Identifying patient- and system-level interventions that can shorten or eliminate care delays could help reduce rates of limb loss.

Mental Health Conditions and Hospitalizations for Ambulatory Care Sensitive Conditions Among Veterans with Diabetes

BACKGROUND

Veterans with diabetes and mental health conditions have a higher risk for suboptimal care and complications related to their diseases than veterans with diabetes who do not have mental health conditions. We hypothesized that among veterans with diabetes, patients with mental health conditions are more likely to be hospitalized for ambulatory care sensitive conditions (ACSC) than those without mental health conditions.

OBJECTIVES

To examine the association between depression, anxiety, and serious mental illness and hospitalizations for ACSC among veterans with diabetes after controlling for demographics and comorbidities.

METHODS

We used a retrospective cohort design with merged Veterans Health Administration (VHA) and Medicare electronic health records from 2008 to 2010. Andersen's Behavioral Model of Health Services Use was used to select the variables associated with hospitalizations for ACSC (ie, predisposing, enabling and need characteristics, personal health practices, and external environment). We used chi-square tests and logistic regressions for our analyses.

RESULTS

Among the dual VHA/Medicare-enrolled veterans with any hospitalization in 2010, 30% had hospitalizations for ACSC. Veterans with diabetes and co-occurring depression were at increased likelihood to be hospitalized for ACSC, after adjusting for all other covariates (adjusted odds ratio, 1.08; 95% confidence interval, 1.04-1.11). Similar findings were observed for anxiety. Veterans with serious mental illness were as likely as veterans without serious mental illness to be hospitalized for ACSC.

CONCLUSION

Veterans with depression and anxiety were more likely to be hospitalized for any or acute ACSC than veterans without mental health conditions. Patients hospitalized for acute ACSC were more susceptible than patients hospitalized for chronic ACSC to have mental health conditions. As the VHA continues to evolve from care provider to community care payer (per the Veterans Affairs MISSION Act), our results highlight the ongoing importance of care coordination and communication between payers and providers.

Risk of Ipsilateral Reamputation Following an Incident Toe Amputation Among U.S. Military Veterans With Diabetes, 2005-2016

OBJECTIVE

To assess whether the risk of subsequent lower-limb amputations and death following an initial toe amputation among individuals with diabetes has changed over time and varies by demographic characteristics and geographic region.

RESEARCH DESIGN AND METHODS

Using Veterans Health Administration (VHA) electronic medical records from 1 October 2004 to 30 September 2016, we determined risk of subsequent ipsilateral minor and major amputation within 1 year after an initial toe/ray amputation among veterans with diabetes. To assess changes in the annual rate of subsequent amputation over time, we estimated age-adjusted incidence of minor and major subsequent ipsilateral amputation for each year, separately for African Americans (AAs) and whites. Geographic variation was assessed across VHA markets (n = 89) using log-linear Poisson regression models adjusting for age and ethnoracial category.

RESULTS

Among 17,786 individuals who had an initial toe amputation, 34% had another amputation on the same limb within 1 year, including 10% who had a major ipsilateral amputation. Median time to subsequent ipsilateral amputation (minor or major) was 36 days. One-year risk of subsequent major amputation decreased over time, but risk of subsequent minor amputation did not. Risk of subsequent major ipsilateral amputation was higher in AAs than whites. After adjusting for age and ethnoracial category, 1-year risk of major subsequent amputation varied fivefold across VHA markets.

CONCLUSIONS

Nearly one-third of individuals require reamputation following an initial toe amputation, although risks of subsequent major ipsilateral amputation have decreased over time. Nevertheless, risks remain particularly high for AAs and vary substantially geographically.

Racial differences in trends of serious hypoglycemia among higher risk older adults in US Veterans Health Administration, 2004-2015: Relationship to comorbid conditions, insulin use, and hemoglobin A1c level

AIMS

To evaluate temporal trends in racial/ethnic groups in rates of serious hypoglycemia among higher risk patients dually enrolled in Veterans Health Administration and Medicare fee-for-service and assess the relationship(s) between hypoglycemia rates, insulin/secretagogues and comorbid conditions.

METHODS

Retrospective observational serial cross-sectional design. Patients were ≥65 years receiving insulin and/or secretagogues. The primary outcome was the annual (period prevalence) rates (2004-2015), per 1000 patient years, of serious hypoglycemic events, defined as hypoglycemic-related emergency department visits or hospitalizations.

RESULTS

Subjects were 77-83% White, 7-10% Black, 4-5% Hispanic, <2% women; 38-58% were ≥75 years old; 72-75% had ≥1 comorbidity. In 2004-2015, rates declined from 63.2 to 33.6(-46.9%) in Blacks; 29.7 to 20.3 (-31.6%) in Whites; and 41.8 to 29.6 (-29.3%) in Hispanics. The Black-White rate differences narrowed regardless of insulin use, hemoglobin A1c level, and frequency and various combinations of comorbid conditions. Among insulin users, the Black-White contrast decreased from 34.7 (98.5 vs. 63.8) in 2004 to 13.2 (43.6 vs. 30.4) in 2015; in non-insulin users, the contrast was 25.7 (44.1 vs. 18.4) in 2004 and 10.1 (18.9 vs. 8.8) in 2015.

CONCLUSION

Marked declines in serious hypoglycemia events occurred across race, medications, and comorbidities, suggesting significant changes in clinical practice.

Results of 15 Gy HDR-BT boost plus EBRT in intermediate-risk prostate cancer: Analysis of over 500 patients

PURPOSE/OBJECTIVE

To report biochemical control associated with single fraction 15 Gy high-dose-rate brachytherapy (HDR-BT) boost followed by external beam radiation (EBRT) in patients with intermediate-risk prostate cancer.

MATERIALS AND METHODS

A retrospective chart review of all patients with intermediate-risk disease treated with a real-time ultrasound-based 15 Gy HDR-BT boost followed by EBRT between 2009 and 2016 at a single quaternary cancer center was performed. Freedom from biochemical failure (FFBF), cumulative incidence of androgen deprivation therapy use for biochemical or clinical failure post-treatment (CI of ADT) and metastasis-free survival (MFS) outcomes were measured.

RESULTS

518 patients met the inclusion criteria for this study. Median age at HDR-BT was 67 years (IQR 61-72). 506 (98%) had complete pathologic information available. Of these, 146 (28%) had favorable (FIR) and 360 (69%) had unfavorable (UIR) intermediate-risk disease. 83 (16%) received short course hormones with EBRT + HDR. Median overall follow-up was 5.2 years. FFBF was 91 (88-94)% at 5 years. Five-year FFBF was 94 (89-99)% and 89 (85-94)% in FIR and UIR patients, respectively (p = 0.045). CI of ADT was 4 (2-6)% at 5 years. Five-year CI of ADT was 1 (0-3)% and 5 (2-8)% in FIR and UIR patients, respectively (p = 0.085). MFS was 97 (95-98)% at 5 years. Five-year MFS was 100 (N/A-100)% and 95 (92-98)% in FIR and UIR patients, respectively (p = 0.020).

CONCLUSION

In this large cohort of intermediate-risk prostate cancer patients, 15 Gy HDR-BT boost plus EBRT results in durable biochemical control and low rates of ADT use for biochemical failure.

Absolute percentage of biopsied tissue positive for Gleason pattern 4 disease (APP4) appears predictive of disease control after high dose rate brachytherapy and external beam radiotherapy in intermediate risk prostate cancer

BACKGROUND AND PURPOSE

To identify if, in intermediate risk prostate cancer (IR-PCa), the absolute percentage of biopsied tissue positive for pattern 4 disease (APP4) may be a predictor of outcome.

MATERIALS AND METHODS

411 patients with IR-PCa were retrospectively reviewed. APP4 was calculated based on biopsy reports. Multivariable competing risk analysis was then performed on optimized APP4 cutpoints to predict for biochemical failure (BF), androgen deprivation use for BF (ADT-BF) and development of metastases (MD).

RESULTS

Median follow-up for the cohort was 5.2 (Inter Quartile Range: 2.9-6.6) years. Median baseline PSA was 7.3 (5.3-9.8) ng/mL. 234 (56.9%) patients had T1 and 177 (43.1%) had T2 disease. Median APP4 was 2.00 (0.75-7.50)%. 38 (9.3%) patients experienced BF. The optimal cutpoint of APP4 for BF was >3.3% with an area under the curve (AUC) of 0.66. 17 (4.1%) received ADT-BF. The ADT-BF cutpoint was >6.6% with an AUC of 0.72. Eight (2.0%) developed MD. The MD cutpoint was >17.5% with an AUC of 0.86. Using APP4 >3.3 vs ≤ 3.3, log-transformed baseline PSA ln(PSA) (HR 2.5, 1.1-6.1; p = 0.037) and APP4 (HR 2.3, 1.1-4.7; p = 0.031) predicted for BF. Using APP4 >6.6 vs ≤ 6.6, ln(PSA) (HR 4.2, 1.4-12.4; p = 0.010) and APP4 (HR 3.7, 1.4-10.0; p = 0.009) were predictive of ADT-BF. APP4 >17.5 vs ≤ 17.5 alone was predictive of MD (HR 25.7, 4.9-135.3; p < 0.001).

CONCLUSION

APP4 cutpoints of >3.3%, >6.6% and >17.5% were strongly associated with increased risk of BF, ADT-BF and developing MD respectively. These findings may inform future practice when treating IR-PCa but require external validation.

Dizziness, Vertigo, and Mental Health Comorbidity in Gulf War Veterans

BACKGROUND

Gulf War Illness (GWI) is a chronic condition involving symptoms across multiple body systems. Previous research has implicated the vestibular system as a potential underlying factor in the symptoms experienced by veterans with GWI, due in part to exposure to potentially ototoxic chemicals and events.

PURPOSE

To characterize the presence of vertigo and dizziness symptoms in a sample of veterans with GWI using validated self-report instruments, accounting for mental health comorbidities.

RESEARCH DESIGN

This is a case series, follow-up, prospective interview of clinical veterans; results presented are purely descriptive.

STUDY SAMPLE

Our sample of 50 veterans was a follow-up to a case series of clinical Gulf War veterans evaluated at the War Related Illness and Injury Study Center.

DATA COLLECTION AND ANALYSIS

Veterans participated in a 70-min phone interview where the following questionnaires were administered: Vertigo Symptom Scale (VSS), Patient Health Questionnaire (depression scale), Patient Health Questionnaire (somatization scale), Beck Anxiety Inventory, Posttraumatic Stress Disorder (PTSD) Checklist, Defense and Veterans Brain Injury Center Traumatic Brain Injury Questionnaire, and GWI (Kansas) Questionnaire. We used descriptive (mean/median, standard deviation, interquartile range, and percentage) statistics to describe our sample and illuminate possible relationships between measures.

RESULTS

Our primary finding is a substantial report of vertigo symptoms in our sample, according to the VSS. Ninety percent of participants scored above the VSS threshold (>12), suggesting "severe dizziness." The most commonly endorsed symptom on the VSS was "headache or pressure in the head."

CONCLUSIONS

We conclude that there is significant burden of vertigo symptoms in veterans with GWI, suggesting a need for objective tests of vestibular function in this population. Furthermore, the relationship between symptoms of vertigo and dizziness, vestibular function, and PTSD warrants further exploration using objective measures.

An expanded prevention quality diabetes composite: Quantifying the burden of preventable hospitalizations for older adults with diabetes

AIM

To expand the existing United States Agency for Health Research and Quality (AHRQ) Diabetes composite (AHRQ-DC) to include additional preventable hospitalizations specific or relevant to diabetes.

METHODS

A cross-sectional analysis of 834,696 veteran patients with diabetes aged ≥65 years in 2012. An Expanded Diabetes Composite (Expanded-DC) was developed utilizing: (1) the diabetes-specific category: the AHRQ-DC (short-term and long-term complications, uncontrolled diabetes, lower extremity amputations) and two proposed conditions: hypoglycemia and lower extremity ulcers/inflammation/infections (LEU) and (2) the diabetes-relevant category: the AHRQ-Acute Composite (dehydration, pneumonia, urinary tract infections) and one proposed condition, acute kidney injury (AKI).

RESULTS

The study population was 98% male, 80% White, 10% Black, and 5% Hispanic; 71% had complex comorbidities. There were 64,243 (77.0 admissions/1000 patients) hospitalizations in the Expanded-DC, compared to 13,523 (16.2) in the AHRQ-DC, a 4.7 fold increase. Hospitalizations from AHRQ-Acute Composite and the three proposed conditions added 79% to the Expanded-DC. LEU and hypoglycemia added 39% to the diabetes-specific category. AKI added 18% to the diabetes-relevant category. Blacks incurred more preventable hospitalizations (85.9) than Whites (74.7); as did patients with complex comorbidities (93.6) versus those without (34.6).

CONCLUSION

The AHRQ-DC substantially underestimates rates of clinically important preventable hospitalizations in older diabetes patients.

State-Level Variability in Veteran Reliance on Veterans Health Administration and Potentially Preventable Hospitalizations: A Geospatial Analysis

Most Veterans who use the Veterans Health Administration (VHA) also utilize private-sector health care providers. To better inform local and regional health care planning, we assessed the association between reliance on VHA ambulatory care and total and system-specific preventable hospitalization rates (PHRs) at the state level. We conducted a retrospective dynamic cohort study using Veterans with diabetes mellitus, aged 66 years or older, and dually enrolled in VHA and Medicare parts A and B from 2004 to 2010. While controlling for median age and proportion of males, we measured the association between reliance on VHA ambulatory care and PHRs at the state level using multivariable ordinary least square regression, geographically weighted regression, and generalized additive models. We measured geospatial patterns in PHRs using global Moran’s I and univariate local indicator spatial analysis. Approximately 30% of hospitalized Veterans experienced a preventable hospitalization. Reliance on VHA ambulatory care at the state level ranged from 13.92% to 67.78% and was generally not associated with PHRs. Geospatial analysis consistently identified a cluster of western states with low PHRs from 2006 to 2010. Given the generally low reliance on VHA ambulatory care and lack of association between this reliance and PHRs, policy changes to improve Veterans’ health care outcomes should address private-sector care in addition to VHA care.

Inter-observer agreement in GTV delineation of bone metastases on CT and impact of MR imaging: A multicenter study

BACKGROUND AND PURPOSE

The use of Stereotactic Body Radiotherapy (SBRT) for bone metastases is increasing rapidly. Therefore, knowledge of the inter-observer differences in tumor volume delineation is essential to guarantee precise dose delivery. The aim of this study is to compare inter-observer agreement in bone metastases delineated on different imaging modalities.

MATERIAL AND METHODS

Twenty consecutive patients with bone metastases treated with SBRT were selected. All patients received CT and MR imaging in treatment position prior to SBRT. Five observers from three institutions independently delineated gross tumor volume (GTV) on CT alone, CT with co-registered MRI and MRI alone. Four contours per imaging modality per patient were available, as one set of contours was shared by 2 observers. Inter-observer agreement, expressed in generalized conformity index [CIgen], volumes of contours and contours center of mass (COM) were calculated per patient and imaging modality.

RESULTS

Mean GTV delineated on MR (45.9±52.0cm³) was significantly larger compared to CT-MR (40.2±49.4cm³) and CT (34.8±41.8cm³). A considerable variation in CIgen was found on CT (mean 0.46, range 0.15-0.75) and CT-MRI (mean 0.54, range 0.17-0.71). The highest agreement was found on MRI (mean 0.56, range 0.20-0.77). The largest variations of COM were found in anterior-posterior direction for all imaging modalities.

CONCLUSIONS

Large inter-observer variation in GTV delineation exists for CT, CT-MRI and MRI. MRI-based GTV delineation resulted in larger volumes and highest consistency between observers.

A Proposal for an Out-of-Range Glycemic Population Health Safety Measure for Older Adults With Diabetes

OBJECTIVE

To evaluate patient-level glycemic control and facility variation of a proposed out-of-range (OOR) measure (overtreatment [OT] [HbA_1c <7% (53 mmol/mol)] or undertreatment [UT] [>9% (75 mmol/mol)]) compared with the standard measure (SM) (HbA_1c <8% [64 mmol/mol]) in high-risk older adults.

RESEARCH DESIGN AND METHODS

Veterans Health Administration patients ≥65 years of age in 2012 who were taking antihyperglycemic agents in 2013 were identified. Patient-level rates and facility-level rates/rankings were calculated by age and comorbid illness burden.

RESULTS

We identified 303,097 patients who were taking antiglycemic agents other than metformin only. The study population comprised 193,689 patients with at least one significant medical, neurological, or mental health condition; 98.2% were taking a sulfonylurea and/or insulin; 55.2% were aged 65-75 years; and 44.8% were aged >75 years. The 47.4% of patients 65-75 years met the OOR measure (33.4% OT, 14% UT), and 65.7% met the SM. For patients aged >75 years, rates were 48.1% for OOR (39.2% OT; 8.9% UT) and 73.2% for SM. Facility-level rates for OOR for patients aged 65-75 years ranged from 33.7 to 60.4% (median 47.4%), with a strong inverse correlation (ρ = -0.41) between SM and OOR performance rankings. Among the best-performing 20% facilities on the SM, 14 of 28 ranked in the worst-performing 20% on the OOR measure; 12 of 27 of the worst-performing 20% facilities on the SM ranked in the best-performing 20% on the OOR measure.

CONCLUSIONS

Facility rankings that are based on an SM (potential benefits) and OOR measure (potential risks) differ substantially. An OOR for high-risk populations can focus quality improvement on individual patient evaluation to reduce the risk for short-term harms.

Impact of a national specialty e-consultation implementation project on access

OBJECTIVES

To assess the early impact of implementation of the electronic consults (e-consults) initiative by the Veterans Health Administration (VHA), designed to improve specialty care access.

STUDY DESIGN

Observational cohort study exploiting a natural experiment begun in May 2011 at 12 VHA medical centers and expanded to 122 medical centers by December 2013.

METHODS

The following were assessed: 1) growth of e-consults by VHA regional networks, medical centers, and specialty; 2) location of patient's primary care provider (medical center vs community-based outpatient clinic [CBOC]); 3) potential patient miles needed to travel for a specialty care face-to-face consult in place of the observed e-consults using estimated geodesic distance; 4) use of specialty care subsequent to the e-consult.

RESULTS

Of 11,270,638 consults completed in 13 clinics of interest, 217,014 were e-consults (adjusted rate, 1.93 e-consults per 100 consults). The e-consult rate was highest in endocrinology (5.0 per 100), hematology (3.0 per 100), and gastroenterology (3.0 per 100). The percentage of e-consult patients with CBOC-based primary care grew from 28.5% to 44.4% in the first year of implementation and to 45.6% at year 3. Of those e-consult patients from community clinics, the average potential miles needed to travel was 72.1 miles per patient (SD = 72.6; median = 54.6; interquartile range = 17.1-108), translating to a potential savings of 6,875,631 total miles and travel reimbursement costs of $2,853,387.

CONCLUSIONS

E-consult volume increased significantly since inception within many medical and surgical specialties. For patients receiving primary care at one of more than 800 CBOCs, e-consults may decrease travel burden and direct travel costs for patients.

Cost of lower-limb amputation in U.S. veterans with diabetes using health services data in fiscal years 2004 and 2010

The purpose of this study was to estimate healthcare costs associated with diabetes-related lower-limb amputations (LLAs) within the Veterans Health Administration (VHA). We performed a cross-sectional comparative analysis of 3,381 VHA clinic users in fiscal year (FY) 2004 and 3,403 clinic users in FY2010 identified as having type 2 diabetes mellitus and nontraumatic LLA. LLA expenditures related to inpatient medical, inpatient surgical, and outpatient care were estimated using VHA Health Economics Resource Center average cost files. LLA-related pharmaceutical costs were obtained from VHA Decision Support System national extract files. From the Department of Veterans Affairs (VA) perspective, the mean cost associated with care for diabetes-related LLA per patient in the VA healthcare system in FY2004 was $50,351 (95% confidence interval [CI] = 48,939-51,803) in U.S. dollars; the total cost for all 3,381 patients was $170,236,037. In FY2010, cost per patient rose to $60,647 (95% CI = 59,143-62,188), with a total cost of $206,380,331 for 3,403 patients. In the VHA healthcare system, the economic burden associated with LLAs in patients with diabetes exceeded $200,000,000 in FY2010. This suggests that further improvements in care of patients with diabetes could be associated with significant cost savings.

Variability in estimated glomerular filtration rate values is a risk factor in chronic kidney disease progression among patients with diabetes

Background

It is unknown whether variability of estimated Glomerular Filtration Rate (eGFR) is a risk factor for dialysis or death in patients with chronic kidney disease (CKD). This study aimed to evaluate variability of estimated Glomerular Filtration Rate (eGFR) as a risk factor for dialysis or death to facilitate optimum care among high risk patients.

Methods

A longitudinal retrospective cohort study of 70,598 Veterans Health Administration veteran patients with diabetes and CKD (stage 3–4) in 2000 with up to 5 years of follow-up. VHA and Medicare files were linked to derive study variables. We used Cox proportional hazards models to evaluate association between time to initial dialysis/death and key independent variables: time-varying eGFR variability (measured by standard deviation (SD)) and eGFR means and slopes while adjusting for prior hospitalizations, and comorbidities.

Results

There were 76.7% older than 65 years, 97.5% men, and 81.9% Whites. Patients were largely in early stage 3 (61.2%), followed by late stage 3 (28.9%), and stage 4 (9.9%); 29.1%, 46.8%, and 73.3%, respectively, died or had dialysis during the follow-up. eGFR SDs (median: 5.8, 5.1, and 4.0 ml/min/1.73 m² ) and means (median: 54.1, 41.0, 27.2 ml/min/1.73 m²) from all two-year moving intervals decreased as CKD advanced; eGFR variability (relative to the mean) increased when CKD progressed (median coefficient of variation: 10.9, 12.8, and 15.4). Cox regressions revealed that one unit increase in a patient’s standard deviation of eGFRs from prior two years was significantly associated with about 7% increase in risk of dialysis/death in the current year, similarly in all three CKD stages. This was after adjusting for concurrent means and slopes of eGFRs, demographics, prior hospitalization, and comorbidities. For example, the hazard of dialysis/death increased by 7.2% (hazard ratio:1.072; 95% CI = 1.067, 1.080) in early stage 3.

Conclusion

eGFR variability was independently associated with elevated risk of dialysis/death even after controlling for eGFR means and slopes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0025-5) contains supplementary material, which is available to authorized users.

Assessing potential glycemic overtreatment in persons at hypoglycemic risk

IMPORTANCE

Although serious hypoglycemia is a common adverse drug event in ambulatory care, current performance measures do not assess potential overtreatment.

OBJECTIVE

To identify high-risk patients who had evidence of intensive glycemic management and thus were at risk for serious hypoglycemia.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study of patients in the Veterans Health Administration receiving insulin and/or sulfonylureas in 2009.

MAIN OUTCOMES AND MEASURES

Intensive control was defined as the last hemoglobin A1c (HbA1c) measured in 2009 that was less than 6.0%, less than 6.5%, or less than 7.0%. The primary outcome measure was an HbA1c less than 7.0% in patients who were aged 75 years or older who had a serum creatinine value greater than 2.0 mg/dL or had a diagnosis of cognitive impairment or dementia. We also assessed the rates in patients with other significant medical, neurologic, or mental comorbid illness. Variation in rates of possible glycemic overtreatment was evaluated among 139 Veterans Health Administration facilities grouped within 21 Veteran Integrated Service Networks.

RESULTS

There were 652,378 patients who received insulin and/or a sulfonylurea with an HbA1c test result. Fifty percent received sulfonylurea therapy without insulin; the remainder received insulin therapy. We identified 205,857 patients (31.5%) as the denominator for the primary outcome measure; 11.3% had a last HbA1c value less than 6.0%, 28.6% less than 6.5%, and 50.0% less than 7.0%. Variation in rates by Veterans Integrated Service Network facility ranged 8.5% to 14.3%, 24.7% to 32.7%, and 46.2% to 53.4% for HbA1c less than 6.0%, less than 6.5%, and less than 7.0%, respectively. The magnitude of variation by facility was larger, with overtreatment rates ranging from 6.1% to 23.0%, 20.4% to 45.9%, and 39.7% to 65.0% for HbA1c less than 6.0%, less than 6.5%, and less than 7.0%, respectively. The maximum rate was nearly 4-fold compared with the minimum rates for HbA1c less than 6.0%, followed by 2.25-fold for HbA1c less than 6.5% and less than 2-fold for HbA1c less than 7.0%. When comorbid conditions were included, 430,178 patients (65.9%) were identified as high risk. Rates of overtreatment were 10.1% for HbA1c less than 6.0%, 25.2% for less than 6.5%, and 44.3% for less than 7.0%.

CONCLUSIONS AND RELEVANCE

Patients with risk factors for serious hypoglycemia represent a large subset of individuals receiving hypoglycemic agents; approximately one-half had evidence of intensive treatment. A patient safety indicator derived from administrative data can identify high-risk patients for whom reevaluation of glycemic management may be appropriate, consistent with meaningful use criteria for electronic medical records.

Does diabetes care differ by type of chronic comorbidity?: An evaluation of the Piette and Kerr framework

OBJECTIVE

To evaluate the relationship between diabetes care and types of comorbidity, classified by the degree to which their treatment is concordant with that for diabetes.

RESEARCH DESIGN AND METHODS

Retrospective cohort study (fiscal year [FY] 2001 to FY 2004) of 42,826 veterans with new-onset diabetes in FY 2003. Veterans were classified into five chronic comorbid illness groups (CCIGs): none, concordant only, discordant only, both concordant and discordant, and dominant. Five diabetes-related care measures were assessed in FY 2004 (guideline-consistent testing and treatment goals for HbA(1c) and LDL cholesterol and diabetes-related outpatient visits). Analyses included logistic regressions adjusting for age, race, sex, marital status, priority code, and interaction between CCIGs and visit frequency.

RESULTS

Only 20% of patients had no comorbidities. Mean number of visits per year ranged from 7.8 (no CCIG) to 17.5 (dominant CCIG). In unadjusted analyses, presence of any illness was associated with equivalent or better care. In the fully adjusted model, we found interaction between CCIG and visit frequency. When visits were <7 per year, the odds of meeting the goal of HbA(1c) <8% were similar in the concordant (odds ratio 0.96 [95% CI 0.83-1.11]) and lower in the discordant (0.90 [0.81-0.99]) groups compared with the no comorbidity group. Among patients with >24 visits per year, these odds were insignificant. Dominant CCIG was associated with substantially reduced care for glycemic control for all visit categories and for lipid management at all but the highest visit category.

CONCLUSIONS

Our study indicates that diabetes care varies by types of comorbidity. Concordant illnesses result in similar or better care, regardless of visit frequency. Discordant illnesses are associated with diminished care: an effect that decreases as visit frequency increases.

Estimating utilities for chronic kidney disease, using SF-36 and SF-12-based measures: challenges in a population of veterans with diabetes

PURPOSE

Using transformations of existing quality-of-life data to estimate utilities has the potential to efficiently provide investigators with utility information. We used within-method and across-method comparisons and estimated disutilities associated with increasing chronic kidney disease (CKD) severity.

METHODS

In an observational cohort of veterans with diabetes (DM) and pre-existing SF-36/SF-12 responses, we used six transformation methods (SF-12 to EQ-5D, SF-36 to HUI2, SF-12 to SF-6D, SF-36 to SF-6D, SF-36 to SF-6D (Bayesian method), and SF-12 to VR-6D) to estimate unadjusted utilities. CKD severity was staged using glomerular filtration rate estimated from serum creatinines, with the modification of diet in renal disease formula. We then used multivariate regression to estimate disutilities specifically associated with CKD severity stage.

RESULTS

Of 67,963 patients, 22,273 patients had recent-onset DM and 45,690 patients had prevalent DM. For the recent-onset group, the adjusted disutility associated with CKD derived from the six transformation methods ranged from 0.0029 to 0.0045 for stage 2; -0.004 to -0.0009 for early stage 3; -0.017 to -0.010 for late stage 3; -0.023 to -0.012 for stage 4; -0.078 to -0.033 for stage 5; and -0.012 to -0.001 for ESRD/dialysis.

CONCLUSION

Disutility did not increase monotonically as CKD severity increased. Differences in disutilities estimated using the six different methods were found. Both findings have implications for using such estimates in economic analyses.

Risk of hypoglycemia in older veterans with dementia and cognitive impairment: implications for practice and policy

OBJECTIVES

To examine the relationship between management of diabetes mellitus and hypoglycemia in older adults with and without dementia and cognitive impairment.

DESIGN

Cross-sectional database analysis of veterans aged 65 years and older stratified according to dementia, cognitive impairment, age, antiglycemic medications, and glycosylated hemoglobin (Hba1c) level.

SETTING

Research database with linked clinical, laboratory, pharmacy, and International Classification of Diseases, Ninth Revision, Clinical Modification, codes.

PARTICIPANTS

Four hundred ninety-seven thousand nine hundred veterans aged 65 and older with diabetes mellitus who obtained services from the Department of Veterans Affairs in fiscal years (FYs) 2002 and 2003.

MEASUREMENTS

Hypoglycemia, the outcome variable, was identified from outpatient visits, emergency department and inpatient admission codes in FY2003. Independent variables (FY2002-03) included dementia and cognitive impairment, comorbid conditions, extended care and nursing home stays, demographics, antiglycemic medication, and HbA1c levels.

RESULTS

Prevalence of combined dementia and cognitive impairment was 13.1% for individuals aged 65 to 74 and 24.2% for those aged 75 and older. Mean HbA1c levels were 7.0 ± 1.3% for all participants and 6.9 ± 1.3% for those with dementia. The proportion of participants taking insulin was higher in those with dementia or cognitive impairment (30%) than in those with neither condition (24%). Of all participants taking insulin, more with dementia (26.5%) and cognitive impairment (19.5%) were hypoglycemic than of those with neither condition (14.4%). For all participants, unadjusted odds ratios (ORs) for hypoglycemia were 2.42 (95% confidence interval (CI) = 2.36-2.48) for dementia and 1.72 (95% CI = 1.65-1.79) for cognitive impairment; adjusted ORs were 1.58 (95% CI = 1.53-1.62) for dementia and 1.13 (95% CI = 1.08-1.18) for cognitive impairment.

CONCLUSION

Diabetes mellitus was managed more intensively in older veterans with dementia and cognitive impairment, and dementia and cognitive impairment were independently associated with greater risk of hypoglycemia.

Assessing the risk of lower extremity amputations using an administrative data-based foot risk index in elderly patients with diabetes

BACKGROUND

The aims of the present study were to derive a foot risk index using administrative data similar to the International Working Group on the Diabetic Foot clinical risk classification scheme and to evaluate its association with the risk of initial lower extremity (through foot or above) amputation (ILEA).

METHODS

Merged Veterans Health Administration administrative and Medicare inpatient and outpatient claims data for a historical cohort of Veterans Health Administration users with diabetes were analyzed. Individuals with diabetes, aged ≥67 years in 1999, were classified into seven foot risk categories (where 0=no foot risk conditions; and 6=severe foot conditions). The outcome variable was the incidence of an ILEA over the period 2000-2004. Foot risk was derived from 1998 to 1999, and other independent variables were derived from 1999. The associations between foot risk category and risk of ILEA were evaluated using Cox proportional hazards regression models.

RESULTS

Of 255,534 individuals with diabetes, 54.8% had a documented foot condition in 1999 and 6869 (26.9 per 1000) had an ILEA over the period 2000-2004. We found increased rates of ILEAs as foot risk increased. Based on a Cox regression model containing all independent variables, the hazard ratios for risk of amputation increased progressively from 1.13 (95% CI 1.00-1.28) for the lowest foot risk category to 6.75 (95% CI 6.31-7.23) for the highest foot risk category, compared with individuals without defined foot conditions.

CONCLUSIONS

An administrative data-derived foot risk category was associated with risk of ILEA in a risk level-dependent pattern.

Trends in initial lower extremity amputation rates among Veterans Health Administration health care System users from 2000 to 2004

OBJECTIVE

To evaluate temporal trends in rates of initial lower extremity amputation (ILEA) among patients with diabetes in the Veterans Health Administration (VHA).

RESEARCH DESIGN AND METHODS

Retrospective administrative data analysis of VHA clinic users with diabetes in fiscal years (FY) 2000 to 2004 (1 October 1999-30 September 2004). We calculated annual age- and sex-standardized rates of initial major, minor, and total amputations for the overall population and for various racial/ethnic groups (African Americans, Hispanics, and whites). Trends in ILEA risk were evaluated with and without adjustment for demographic characteristics and other potential risk factors, including presence of microvascular and macrovascular diseases, and antiglycemic treatment.

RESULTS

Study populations of VHA patients with diabetes and without prior amputations ranged from 405,580 in FY 2000 to 739,377 in FY 2004. Age- and sex-standardized ILEA rates decreased by 34% (7.08/1,000 patients in FY 2000 to 4.65/1,000 patients in FY 2005) during the 5-year period. Minor and major amputation rates decreased by 33% (4.59 to 3.06/1,000) and 36% (2.49 to 1.59/1,000), respectively. Of major amputations, below-knee rates decreased from 1.08 to 0.87/1,000 (-19%), and above-knee decreased from 1.41 to 0.72/1,000 (-49%). Similar trends were seen for all racial groups. ILEA risk decreased by 28% (odds ratio 0.72 [95% CI 0.68-0.75]) when FY 2004 was compared with FY 2000 in the model, adjusting for demographic characteristics. This risk decrease was 22% in the model adjusting for all independent variables (odds ratio 0.78 [95% CI 0.74-0.82]).

CONCLUSIONS

Downward 5-year trends in ILEA rates were observed for all amputation levels and among all racial groups, even after adjustment for risk differences over time.

Hidden complexities in assessment of glycemic outcomes: are quality rankings aligned with treatment?

OBJECTIVE

To evaluate facility rankings in achieving <7% A1C levels based on the complexity of glycemic treatment regimens using threshold and continuous measures.

RESEARCH DESIGN AND METHODS

We conducted a retrospective administrative data analysis of Veterans Health Administration Medical Centers in 2003-2004. Eligible patients were identified using National Committee for Quality Assurance (NCQA) measure specifications. A complex glycemic regimen (CGR) was defined as receipt of insulin or three oral agents. Facilities were ranked using five ordinal categories based up both z score distribution and statistical significance (P < 0.05). Rankings using the NCQA definition were compared with a subset receiving CGRs using both a <7% threshold and a continuous measure awarding proportional credit for values between 7.9 and <7.0%. Ranking correlation was assessed using the Spearman correlation coefficient.

RESULTS

A total of 203,302 patients (mean age 55.2 years) were identified from 127 facilities (range 480-5,411, mean 1,601); 26.7% (17.9-35.2%) were receiving CGRs, including 22.0% receiving insulin. Mean A1C and percent achieving A1C <7% were 7.48 and 48% overall and 8.32 and 24.8% for those receiving CGRs using the threshold measure; proportion achieved was 60.1 and 37.2%, respectively, using the continuous measure. Rank correlation between the overall and CGR subset was 0.61; 8 of 24 of the highest or lowest ranked facilities changed to nonsignificance status; an additional five sites changed rankings.

CONCLUSIONS

Facility rankings in achieving the NCQA <7% measure as specified differ markedly from rankings using the CGR subset. Measurement for public reporting or payment should stratify rankings by CGR. A continuous measure may better align incentives with treatment intensity.

Individualized, non-age-based glycemic control in elderly veterans with diabetes

OBJECTIVE

To examine the role of age and endocrinology care in glycemic testing and control in elderly veterans with diabetes.

RESEARCH DESIGN AND METHODS

In this retrospective study of Veterans Health Administration clinic users aged > or = 65 years with diabetes, we compared glycemic testing and poor glycemic control (A1C > 9%) between older (> or = 75 years) and younger (65-74 years) veterans in the year 2000.

RESULTS

Without adjustment, rates for glycemic testing were 70.2% in older and 71.1% in younger veterans, and those for poor control were 9.4% in older and 12.8% in younger veterans. After adjustment, older veterans had 1.8% lower probability of glycemic testing and 2.9% lower probability of poor control than younger veterans. Endocrinology care was associated with a higher probability of both glycemic testing (9.7%) and poor control (1.0%), regardless of age.

CONCLUSIONS

Glycemic testing and control and effect of endocrinology care were comparable in older and younger veterans with diabetes.

Survival benefit of nephrologic care in patients with diabetes mellitus and chronic kidney disease

BACKGROUND

The association of nephrologic care and survival in patients with diabetes mellitus and chronic kidney disease is unknown.

METHODS

Using data from 1997 to 2000, we conducted a retrospective cohort study of Veterans Health Administration clinic users having diabetes mellitus and stage 3 or 4 chronic kidney disease. The baseline period was 12 months and median follow-up was 19.3 months. Degree of consistency of visits to a nephrologist, defined as the number of calendar quarters in which there was 1 visit or more (range, 0-4 quarters), and covariates were calculated from the baseline period. The outcome measure was dialysis-free death.

RESULTS

Of 39,031 patients, 70.0%, 22.4%, and 7.6% had early stage 3, late stage 3, and stage 4 chronic kidney disease, respectively, and 3.1%, 9.5%, and 28.2%, respectively, visited a nephrologist. Dialysis-free mortality rates were 9.6, 14.1, and 19.4, respectively, per 100 person-years. More calendar quarters with visits to a nephrologist were associated with lower mortality: adjusted hazard ratios were 0.80 (95% confidence interval, 0.67-0.97), 0.68 (95% confidence interval, 0.55-0.86), and 0.45 (95% confidence interval, 0.32-0.63), respectively, when the groups having 2, 3, and 4 visits were compared with those who had no visits. One visit only was not associated with a difference in mortality when compared with no visits (adjusted hazard ratio,1.02; 95% confidence interval, 0.89-1.16).

CONCLUSIONS

The consistency of outpatient nephrologic care was independently associated in a graded fashion with lower risk of deaths in patients with diabetes and moderately severe to severe chronic kidney disease. However, only a minority of patients had any visits to a nephrologist.

Chronic illness with complexity: implications for performance measurement of optimal glycemic control

OBJECTIVE

To evaluate the association between chronic illness with complexity (CIC) and optimal glycemic control.

PARTICIPANTS

Cross-sectional and longitudinal analyses of Diabetes Epidemiologic Cohort database of Veterans Health Administration (VHA) users with diabetes, less than 75 years old, with HbA1c tests in fiscal year (FY) 1999 and 2000, alive at FY2000 end (N = 95,423).

DESIGN/MEASUREMENTS

Outcomes were HbA1c < 7% in each FY. CIC included three domains: nondiabetes physical illness, diabetes-related, and mental illness/substance abuse conditions. Other independent variables included age, gender, race, marital status, VHA priority status, and diabetes severity. Longitudinal analyses were restricted to patients with HbA1c >or= 7% in FY1999 and included hospitalizations between final HbA1c's in FY1999 and FY2000. Multiple logistic regressions examined associations between CIC categories and HbA1c.

RESULTS

In FY1999, 33% had HbA1c <7%. In multivariate analyses, patients with nondiabetes physical illness and mental illness/substance abuse were more likely to have HbA1c <7% in FY1999 [adjusted odds ratios for cancer (AOR), 1.31; 95% CI (1.25-1.37); mental illness only, 1.18; 95% CI (1.14-1.22)]. Those with diabetes-related complications were less likely to have HbA1c <7% in FY1999. Associations generally held in FY2000. However, conditions in the mental illness/substance abuse complexity domain were less strongly associated with HbA1c <7%. Macrovascular-related hospitalizations were positively associated with HbA1c <7% [AOR, 1.41; 95% CI (1.34-1.49)].

CONCLUSIONS

The association between CIC and HbA1c <7% is heterogeneous and depends on the domain of complexity. The varying associations of CIC categories with optimal glycemic control suggest the need for appropriate risk adjustment when using HbA1c <7% as a valid performance measure for diabetes quality of care.

The association between mental health functioning and nontraumatic lower extremity amputations in veterans with diabetes

OBJECTIVE

The objective of this study was to evaluate the association between mental health functioning and lower extremity amputations (LEAs) in veterans with diabetes.

METHOD

A retrospective study of 1999 Large Veteran Health Survey (LVHS) respondents with diabetes who were Veterans Health Administration clinic users in fiscal years (FYs) 1998-2000 was performed. The outcome measure was type of LEAs (major, minor and none) in FY 2000. The primary independent variable was mental health functioning [adapted Medical Outcomes Study Short Form-36 mental component summary (MCS) score, with higher being better] from the LVHS. Multinomial logistic regressions were performed to evaluate the association between MCS score and LEAs, adjusting for control variables derived from FY 1999.

RESULTS

Of the 114,890 individuals included in the study, there were 450 (3.9 per 1000 individuals) major and 431 (3.8 per 1000 individuals) minor LEAs in FY 2000. Individuals with major and minor LEAs had lower mean MCS scores than those without LEAs (39.9, 42.2 and 43.4). After controlling for other independent variables, a five-point increase in MCS score was associated with a 5% decrease in the risk of major LEAs (odds ratio [OR]=0.95; 95% confidence interval [95% CI]=[0.94, 0.96]) but was not related to minor LEAs (OR=1.01; 95% CI=[0.97, 1.05]).

CONCLUSION

Footcare programs need to assess individuals for mental health functioning as a risk factor and to develop appropriate interventions to reduce the risk of major amputation.

Evaluation of regional variation in total, major, and minor amputation rates in a national health-care system

BACKGROUND

Health-care systems need actionable information on amputation rates in order to improve foot-care delivery.

OBJECTIVE

To evaluate regional variation in total, major, and minor amputation rates using individual-level data.

METHODS

This was a retrospective cohort study of Veterans Health Administration users with diabetes who were Medicare enrolled between fiscal years 1998 and 2000 (10/1/1997-9/30/2000). The outcome was outlier status, based upon observed-to-expected ratios, for total, major, and minor amputations of 22 regional networks in fiscal year 2000.

RESULTS

331,806 patients incurred a total of 4,037 (12.2 per 1000; range 9.3-16.7 across networks) amputations in fiscal year 2000: 2,271 major amputations (6.8 per 1000; 4.7-9.1) and 1,766 minor amputations (5.3 per 1000; 3.9-7.6). All network outliers based upon the total amputation observed-to-expected ratio were also outliers based on major amputation observed-to-expected ratio. However, two of the five non-outliers based on total amputations were outliers based on major amputations. Simultaneous evaluation of major and minor amputation observed-to-expected ratios demonstrated four patterns of dual outlier status among networks: two networks had lower than expected minor and major amputation rates; two had higher than expected minor and major amputation rates; one network was lower than expected by major but higher by minor amputation rate; one was higher than expected by major but lower by minor amputation rate.

CONCLUSIONS

Simultaneous evaluation of major and minor amputation rates identifies different patterns of regional outlier status compared to total or major amputation rates alone. This strategy may facilitate targeted evaluations of health-care processes and structures.

Facility-level variations in patient-reported footcare knowledge sufficiency: implications for diabetes performance measurement

AIMS

To evaluate medical center variation in self-reported knowledge of footcare practices by veterans at high risk for lower extremity complications.

METHODS

We utilized a previously validated footcare-specific survey from 772 (44% response rate) veterans with diabetes and high-risk foot conditions at eight Veterans Administration facilities that contained items on knowledge of basic (such as how to inspect feet) and specialized self-foot care practices (such as cutting nails and shaving calluses). Linear regression models were used to evaluate facility-level variation in unadjusted and adjusted education (controlling for age, schooling, general, and foot health).

RESULTS

Participants' average age was 67 years, 94% were male and 34% had 13 years of education. The mean facility basic knowledge score on a four-point ordinal scale was 3.1 (range: 2.9-3.3), where 1=no knowledge and 4=enough knowledge. The specialized knowledge score, using the same scale, was 2.52 (range: 2.2-2.8). There were significant (p<0.005) differences among facilities in both unadjusted and adjusted basic and specialized footcare knowledge.

CONCLUSIONS

Patient self-reported footcare knowledge was suboptimal and significantly varied across medical centers with and without adjustment for foot-risk factors, general health, and demographic factors.

Short-term statin exposure is associated with reduced all-cause mortality in persons with diabetes

BACKGROUND

The survival benefit of statins in nontrial populations of persons with diabetes is unknown.

OBJECTIVE

: We sought to determine all-cause mortality in fiscal year 2001 (FY01) after statin initiation in FY 99 and/or FY00 in individuals with diabetes in the Veterans Healthcare Administration (VHA).

METHODS

Using a retrospective longitudinal cohort analysis, we analyzed 201,102 veterans with diabetes from 104 VHA facilities with medical, pharmacy, and laboratory information from VHA and Medicare databases. Patients with statin exposure, defined as having medication possession coverage >50% of eligible days in FY99 and/or FY00, were characterized as initiators if no statin prescription was found in FY98. Otherwise, they were characterized as continuing users. We defined 4 statin exposure groups: FY99 only, FY00 only, both FY99 and 00, and neither year. All-cause mortality was determined in FY01. Propensity score matched comparisons were used to corroborate results from mixed effects logistic models.

RESULTS

FY01 mortality was no different between FY99-only initiators and the nonexposure group (odds ratio [OR] = 1.08, P = 0.429). In contrast, FY00-only and FY99-00 initiator groups showed odds ratio of 0.75 (P < 0.0001) and 0.71 (P < 0.0001), respectively. There was a similar benefit for continuing users. Propensity analysis demonstrated consistent findings. Increased statin adherence from >50% to >75% was associated with increased benefit (OR = 0.71, P < 0.0001 versus OR = 0.62, P = 0.0002).

CONCLUSIONS

One to 2-year statin exposure is associated with a 25% to 29% risk reduction in all-cause mortality of the subsequent year in a high-risk diabetes cohort.

Diabetes care among veteran women with disability

OBJECTIVE

The primary objective of this study was to analyze predictors of diabetes care consistent with performance standards among women Veterans Health Administration (VHA) clinic users with disability enrollment status.

METHODS

This is a retrospective cohort study using VHA and Medicare files of VHA clinic users with diabetes. Diabetes care measures consisted of annual testing for hemoglobin A(1c) (HbA(1c)), low-density lipoprotein cholesterol (LDL-C), and poor HbA(1c) (>9%) and LDL-C (> or =130 mg/dL) control in fiscal year 2000. Chi-square tests and logistic regressions were used to assess subgroup differences in diabetes care. Independent variables included demographic characteristics and physical and psychiatric comorbidities.

POPULATION

Study population was based on veteran women <65 years of age who used VHA clinics; we identified 2,344 women as having coexisting disability and diabetes and 2,766 women with diabetes and without disability.

FINDINGS

Among veteran women with diabetes and disability, 65% received > or =1 HbA(1c) test, and 54% received a LDL-C test; 25% and 30% had poor HbA(1c) and LDL-C control, respectively. In logistic regressions, none of the independent variables had significant effects on poor HbA(1c) or LDL-C control, except that African Americans were more likely to have poor HbA(1c) control than whites. Significant age effects were noted in rates of HbA(1c) and LDL testing. Comparison of diabetes care measures between women with and without disability indicated that those with disability were more likely to receive HbA(1c) and LDL-C tests; no significant differences in HbA(1c) and LDL-C control were noted.

CONCLUSIONS

Disability status of women veterans was not a barrier to diabetes care consistent with performance standards. Our findings suggest that to improve diabetes care, subgroup-specific interventions, rather than a global approach, are warranted.

Facility variation in utilization of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers in patients with diabetes mellitus and chronic kidney disease

OBJECTIVE

To evaluate facility-level variation in prescription rates of angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB) medications for patients with diabetes mellitus (DM) and chronic kidney disease (CKD).

STUDY DESIGN

Retrospective database analysis from 143 Veterans Health Administration facilities.

METHODS

Subjects with DM aged 18 to 75 years were identified as having stage 2-4 CKD using estimated glomerular filtration rate (eGFR) based on an index eGFR in 1999 and a subsequent eGFR 90-365 days later. Whether ACEI/ARB medications were prescribed within 1 year after the index eGFR was determined. Variation in facility-level rates was evaluated separately for subjects age <65 years and 65 to 75 years from facilities with more than 50 subjects per age group.

RESULTS

A total of 103 853 subjects had stage 2 CKD; 51 728, stage 3; and 3233, stage 4. However, 25% of facilities had fewer than 50 patients age <65 years with either stage 3 or 4 CKD. The median (range) facility-level prescription rates of ACEI/ARB for stage 2 and combined stage 3-4 CKD were 58.5% (44.3%-71.2%) and 73.3% (51.7%-84.6%), respectively, for subjects age <65 years; and 56.5% (38.1%-71.4%) and 68.4% (51.6%-80.1%), respectively, for subjects aged 65 to 75 years. Spearman rank correlation between facility rankings by age group was 0.72 for stage 2 (139 facilities) and 0.49 for stage 3-4 (111 facilities) (P < .001).

CONCLUSION

Although ascertainment of prescription rates of ACEI/ARB to CKD patients is feasible using electronic health records, small sample size at the healthcare-system level preclude their utility for public reporting.

Impact of self-reported patient characteristics upon assessment of glycemic control in the Veterans Health Administration

OBJECTIVE

The purpose of this article was to evaluate the impact of self-reported patient factors on quality assessment of Veterans Health Administration medical centers in achieving glycemic control.

RESEARCH DESIGN AND METHODS

We linked survey data and administrative records for veterans who self-reported diabetes on a 1999 national weighted survey. Linear regression models were used to adjust A1C levels in fiscal year 2000 for socioeconomic status (education level, employment, and concerns of having enough food), social support (marital status and living alone), health behaviors (smoking, alcohol use, and exercise level), physical and mental health status, BMI, and diabetes duration. Medical centers were ranked by deciles, with and without adjustment for patient characteristics, on proportions of patients achieving A1C <7 or <8%.

RESULTS

There was substantial medical center level variation in patient characteristics of the 56,740 individuals from 105 centers, e.g., grade school education (mean 15.3% [range 2.3-32.7%]), being retired (38.3% [19.9-59.7%]) or married (65.2% [43.7-77.8%]), food insufficiency (13.9% [7.2-24.6%]), and no reported exercise (43.2% [31.1-53.6%]). The final model had an R(2) of 7.8%. The Spearman rank coefficient comparing the thresholds adjusted only for age and sex to the full model was 0.71 for <7% and 0.64 for <8% (P < 0.0001). After risk adjustment, 4 of the 11 best-performing centers changed at least two deciles for the <7% threshold, and 2 of 11 changed two deciles for the <8% threshold.

CONCLUSIONS

Adjustment for patient self-reported socioeconomic status and health impacts medical center rankings for glycemic control, suggesting the need for risk adjustment to assure valid inferences about quality.