Association between biochemical control and comorbidities in patients with acromegaly: an Italian longitudinal retrospective chart review study

PURPOSE

Achieving biochemical control (normalization of insulin-like growth factor-1 [IGF-1] and growth hormone [GH]) is a key goal in acromegaly management. However, IGF-1 and GH fluctuate over time. The true potential impact of time-varying biochemical control status on comorbidities is unclear and relies on multiple, longitudinal IGF-1 and GH measurements. This study assessed the association between time-varying biochemical control status and onset of selected comorbidities in patients with acromegaly.

METHODS

Medical charts of adults with confirmed acromegaly and ≥ 6 months of follow-up at an Italian endocrinology center were reviewed. Patients were followed from the first diagnosis of acromegaly at the center until loss to follow-up, chart abstraction, or death. Biochemical control status was assessed annually and defined as IGF-1 ≤ the upper limit of normal, or GH ≤ 2.5 µg/L in the few cases where IGF-1 was unavailable. Time-varying Cox models were used to assess the association between biochemical control status and comorbidities.

RESULTS

Among 150 patients, 47% were female, average age at diagnosis was 43.1, and mean length of follow-up was 10.4 years. Biochemical control was significantly associated with a lower hazard of diabetes (HR = 0.36, 95% CI 0.15; 0.83) and cardiovascular system disorders (HR = 0.54, 95% CI 0.31; 0.93), and a higher hazard of certain types of arthropathy (HR = 1.68, 95% CI 1.04; 2.71); associations for other comorbidities did not reach statistical significance.

CONCLUSION

Results further support the importance of achieving biochemical control, as this may reduce the risk of high-burden conditions, including diabetes and cardiovascular system disorders. The association for arthropathy suggests irreversibility of this impairment. Due to limitations, caution is required when interpreting these results.

In-hospital risk of venous thromboembolism and bleeding and associated costs for patients undergoing total hip or knee arthroplasty

OBJECTIVE

Benefits of anti-coagulation for venous thromboembolism (VTE) prevention in total hip and knee arthroplasty (THA/TKA) may be offset by increased risk of bleeding. The aim was to assess in-hospital risk of VTE and bleeding after THA/TKA and quantify any increased costs.

METHODS

Healthcare claims from the Premier Perspective(TM) Comparative Hospital Database (January 2000-September 2008) were selected for subjects ≥ 18 years with ≥ 1 diagnosis code for THA/TKA. VTE was defined as ≥ 1 code for deep vein thrombosis or pulmonary embolism. Bleeding was classified as major/non-major. Incremental in-hospital costs associated with VTE and bleeding were calculated as cost differences between inpatients with VTE or bleeding matched 1:1 with inpatients without VTE or bleeding.

RESULTS

A total of 820,197 inpatient stays were identified: 8042 had a VTE event and 7401 a bleeding event (2740 major bleeding). The risks of VTE, any bleeding, and major bleeding were 0.98, 0.90, and 0.33/100 inpatient stays, respectively. Mean incremental in-hospital costs per inpatient were $2663 for VTE, $2028 for bleeding, and $3198 for major bleeding.

LIMITATIONS

These included possible inaccuracies or omissions in procedures, diagnoses, or costs of claims data; no information on the amount of blood transfused or decreases in the hemoglobin level to evaluate bleeding event severity; and potential biases due to the observational design of the study.

CONCLUSIONS

In-hospital risk and incremental all-cause costs with THA/TKA were higher for VTE than for bleeding. Despite higher costs, major bleeding occurred less frequently than VTE, suggesting a favorable benefit/risk profile for VTE prophylaxis in THA/TKA.

Treatment (trx) patterns of angiogenesis inhibitors in patients (pts) with metastatic renal cell carcinoma (mRCC) in Ireland

383

Background: This study evaluated rates of trx modifications and reasons for these changes among pts treated with angiogenesis inhibitors in Irish clinical practice.

Methods: Data from medical records were retrospectively reviewed at 3 large oncology centers in Ireland for mRCC pts who were ≥ 18 years and received sunitinib (SU) (n=54), sorafenib (n=9), bevacizumab (n=6), or temsirolimus (n=7) as first-line trx from 1/1/2005 to 8/31/2010. Proportions of pts with trx discontinuation (d/c), interruption, or dose change, and reasons for modifications and time to modifications were determined.

Results: Due to small sample sizes in other groups, only results for SU are summarized. 1.9% of pts had prior cytokine therapy. Median first-line trx duration for SU was 8.7 months (mo), while median progression-free survival was 13.8 mo. 87% of patients treated with first-line SU experienced adverse events (AEs); 18.5% experienced grade 3/4 AEs. AEs led to trx modifications in 42.6% of pts. 94.4% of pts started trx on 50 mg QD 4/2 dosing; 33.3% of them were dose reduced to 37.5 mg QD 4/2 with median time to reduction 2.7 mo. Among pts who discontinued trx, 31.6% discontinued within 18 weeks (w) (15.8% within 0-6 w, 7.9% in 7-12 w, and 7.9% in 13-18 w). Among pts who discontinued trx within 18 w, 66.7% discontinued due to AEs.

Conclusions: Over three-quarters of SU pts experienced trx modifications, more than half due to AEs. About 24% of txt discontinuations occurred within the first two cycles. This real-world practice study suggests that treatment tolerability is a challenge for physicians in the clinical care of mRCC pts.

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Pattern of utilization of pegfilgrastim in patients with chemotherapy-induced neutropenia: A retrospective analysis of administrative claims data

9624

Background: Pegfilgrastim is a long-acting granulocyte colony-stimulating factor (G-CSF) used to prevent or treat febrile neutropenia associated with myelosuppressive anticancer therapies. According to the prescribing information, pegfilgrastim should not be administered within 14 days before or 24 hours after cytotoxic chemotherapy because of the potential for myeloid toxicity. This study examined use patterns of pegfilgrastim in real-life practice. Methods: Analysis of health insurance claims data in 2000- 2007 from > 35 large health plans across the US was conducted. Patients who had a cancer diagnosis and chemotherapy within 120 days of their first pegfilgrastim injection were identified. The proportion of pegfilgrastim injections that were followed by administration of chemotherapy within 11 and 9 days was calculated. Analysis was also stratified by cancer type [Non-Hodgkin's lymphoma (NHL), lung, breast]. Results: A total of 13,526 cancer patients received 57,118 pegfilgrastim injections. NHL, lung, and breast cohorts comprised 2,722, 2,772, and 4,955 patients, respectively. Mean age (SD) was 55.0 (11.6) and women represented 65.9% of study population. Among all cancer types, 19.2% of pegfilgrastim injections had a chemotherapy claim within the following 11 days. This pattern of use was the highest in NHL (18.9%), followed by lung (17.1%), and breast (16.2%). Similar results were observed in the 9-day sensitivity analysis (see Table ). Conclusions: Based on the retrospective analysis of this administrative claims database, the use of pegfilgrastim within 11 days of an administration of chemotherapy was observed in 15–20% of cases which is inconsistent with the recommended guidelines. Pegfilgrastim use in these situations may have the potential to increase sensitivity of rapidly dividing myeloid cells to cytotoxic chemotherapy. Further research is being conducted to assess the related clinical and economic impact of this pattern of usage. [Table: see text]

[Table: see text]

Nonadherence to antiepileptic drugs and increased mortality: findings from the RANSOM Study

OBJECTIVES

The primary objective was to investigate whether nonadherence to antiepileptic drugs (AEDs) is associated with increased mortality and the secondary objective to examine whether nonadherence increases the risk of serious clinical events, including emergency department (ED) visits, hospitalizations, motor vehicle accident (MVA) injuries, fractures, and head injuries.

METHODS

A retrospective open-cohort design was employed using Medicaid claims data from Florida, Iowa, and New Jersey from January 1997 through June 2006. Patients aged > or =18 years with > or =1 diagnosis of epilepsy by a neurologist and > or =2 AED pharmacy dispensings were selected. Medication possession ratio (MPR) was used to evaluate AED adherence on a quarterly basis with MPR > or =0.80 considered adherent and <0.80 nonadherent. The association of nonadherence with mortality was assessed using a time-varying Cox regression model adjusting for demographic and clinical confounders. Incidence rates for serious clinical events were compared between adherent and nonadherent quarters using incidence rate ratios (IRRs) with 95% CIs calculated based on the Poisson distribution.

RESULTS

The 33,658 study patients contributed 388,564 AED-treated quarters (26% nonadherent). Nonadherence was associated with an over threefold increased risk of mortality compared to adherence (hazard ratio = 3.32, 95% CI = 3.11-3.54) after multivariate adjustments. Time periods of nonadherence were also associated with a significantly higher incidence of ED visits (IRR = 1.50, 95% CI = 1.49-1.52), hospital admissions (IRR = 1.86, 95% CI = 1.84-1.88), MVA injuries (IRR = 2.08, 95% CI = 1.81-2.39), and fractures (IRR = 1.21, 95% CI = 1.18-1.23) than periods of adherence.

CONCLUSION

These findings suggest that nonadherence to antiepileptic drugs can have serious or fatal consequences for patients with epilepsy.

Costs associated with intravenous (IV) chemotherapy administration in patients with lung cancer

18092

Background: The IV method of chemotherapy administration imposes not only a time burden on patients and facilities, but also has cost implications for payers. This study aims to assess the costs associated with the IV administration of chemotherapies for patients with all forms of lung cancer and for a subset of patients with small cell lung cancer (SCLC) in a large employer-payer claims database. Methods: Using medical claims data from 5.5 million beneficiaries between 01/01/1998 and 01/31/2006, we identified 8,605 patients with lung cancer (ICD-9 codes 162.3–162.9, 176.4, or 197.0) receiving IV chemotherapies. We then identified a subset of 942 patients likely to have SCLC by selecting those receiving chemotherapy regimens primarily used to treat SCLC and excluding patients receiving procedures and treatments often associated with NSCLC. Average total costs per day of IV chemotherapy administration (including drug, administration costs, etc.) were computed for all patients and for the SCLC subset based on the actual amount paid. Costs were also computed separately for: IV chemotherapy drugs, IV chemotherapy administration procedures, and other drugs and services such as IV administration of other drugs to treat side effects of chemotherapies, evaluation and management, and laboratory tests. Results: Average total cost per day of IV chemotherapy administration for all patients was $1,112, with $652 (59%) attributable to IV chemotherapy drugs, $85 (8%) to IV chemotherapy administration procedures, and $375 (34%) to other drugs and services. Among patients with SCLC, average total daily cost was $815, with $423 (52%) attributable to IV chemotherapy drugs, $89 (11%) to IV chemotherapy administration, and $303 (37%) to other drugs and services. Conclusions: IV chemotherapy administration procedures and other visit-related services accounted for 42% and 48% of total costs in patients with all forms of lung cancer and those with SCLC, respectively. The increased availability and use of oral chemotherapy drugs in lung cancer should provide savings to payers by avoiding the costs associated with IV administration.

No significant financial relationships to disclose.

Erythroid response (ER) rates in myelodysplastic syndromes (MDS) patients treated with epoetin alfa (EPO): A meta-analysis using the International Working Group criteria (IWGc) for MDS response

6572

Background: Refractory anemia is a clinical hallmark of MDS. The most consistently used therapy for this anemia is EPO. Prior to the introduction of IWGc in 1997, ER rates varied substantially between studies. The present meta-analysis was undertaken to compare ER rates in studies of EPO-treated patients in MDS when defined by either IWGc or non-IWGc. Methods: A systematic review and data extraction of studies published from 1990–2005 in MDS patients treated with EPO was performed and yielded 21 studies evaluating a total of 895 patients. Pooled estimates of ER rates, stratified by IWGc, were calculated using random-effects meta-analysis methods, which incorporated both between- and within-study variations. Univariate meta-regression analyses were conducted to identify study characteristics that were significant determinants of ER rate. Results: Ten studies (604 patients) used the IWGc to define ER (overall, major, minor), while 11 studies (291 patients) used other definitions. Mean age for all patients was 70.6 years; 45% women. Mean baseline (BL) serum erythropoietin level and proportion of patients with refractory anemia or refractory anemia with ringed sideroblasts were comparable between studies; however, the proportion of transfusion-dependent patients at BL was lower in the IWG studies vs the non-IWG studies (36% vs. 84%, respectively, p<.001). The pooled estimate of ER rate was significantly higher for the IWG studies compared to the non-IWG studies (50.5%, 95% CI: 38.6%-62.3% vs. 27.8%, 95% CI: 22.7%-32.8% respectively, p=.002). Among patients in the IWG studies who achieved an ER, 62% (188/305) achieved a major ER. Studies reporting mean BL serum erythropoietin level <400mU/mL, <65% of patients transfusion-dependent at BL and use of subcutaneous EPO were found to be associated with higher ER rates. Conclusions: This meta-analysis of MDS patients treated with EPO demonstrates significantly higher ER rates in studies utilizing IWGc. These findings may be due to more refined definitions of ER and MDS diagnostic criteria as well as improvement in the management of anemia.

[Table: see text]

Comparison of red blood cell transfusion rates of epoetin alfa and darbepoetin alfa in an inpatient oncology setting

16002

Background: Epoetin alfa (EPO) and darbepoetin alfa (DARB) are used to treat cancer-related anemia and to reduce the requirements for blood transfusions. To date, limited information on the relative effectiveness of these agents in the inpatient setting is available. This analysis evaluated red blood cell (RBC) transfusion rates in cancer patients receiving EPO or DARB during hospitalization. Methods: An analysis of electronic inpatient hospital records from the Premier Perspective Comparative Hospital Database was conducted to compare RBC transfusion rates in cancer patients receiving EPO or DARB therapy. Study subjects were identified through hospitalizations recorded between 07/2002 and 03/2005 from over 500 hospitals nationwide. Patients were required to be ≥18 years old, have a primary admitting diagnosis of cancer and be treated with EPO or DARB during hospitalization. Patients who had received renal dialysis were excluded. To minimize effects of outliers, 5% of patients with extreme doses in each group were excluded from the dosing analysis. In addition to descriptive statistics on transfusion requirements, a multivariate logistic model was employed to isolate the effect of an individual erythropoietic agent on the risk of RBC transfusion after controlling for patient demographics, comorbidities, admission characteristics, use of IV or oral iron and hospitalization severity markers. Results: Among the 24,814 EPO and 2,990 DARB study patients, mean age and gender distribution at admission were similar (age: EPO 65.3 years, DARB 64.5 years; %women: EPO 53%, DARB 55%). Mean cumulative dose per inpatient stay was EPO 61,656 ± 50,274 Units and DARB 259 ± 340 mcg. RBC transfusions occurred in 37.9% of EPO patients compared to 39.8% of DARB patients (p=0.0404). Transfused EPO patients received a mean of 2.24 units versus 2.20 units for DARB patients (p=0.2111). After adjusting for covariates, the multivariate model confirmed that DARB treatment was associated with a higher risk of transfusion compared to EPO (odds ratio: 1.2, 95% CI: 1.1–1.3, p=0.0007). Conclusions: This analysis of inpatients with cancer indicates DARB treatment is associated with a higher risk of receiving RBC transfusion compared to treatment with EPO.

[Table: see text]

The cost-effectiveness of weekly epoetin alfa relative to weekly darbepoetin alfa in patients with chemotherapy-induced anemia

OBJECTIVE

To compare the cost-effectiveness of epoetin alfa (EPO) and darbepoetin alfa (DARB) for the treatment of chemotherapy-induced anemia (CIA), using dosing regimens approved by the FDA (EPO 40,000 U once weekly and DARB 2.25 U once weekly and DARB 2.25 mcg/kg once weekly).

METHODS

The study compared published results of two double-blind, randomized, phase III trials one utilizing EPO (N = 166) and the other, DARB (N = 367). Patients in both trials similar baseline characteristics. Effectiveness was measured as the proportion of EPO or DARB patients who were successfully treated (i.e., did not require blood transfusion) during weeks 0-16 and 5-16, respectively. Estimated drug costs were presented in 2005 USD based on wholesale acquisition cost (WAC) and average drug utilization over 16 weeks. Cost-effectiveness was calculated as the estimated drug costs divided by transfusion effectiveness. Threshold analysis was used to determine the break-even point at which EPO and DARB had the same drug costs.

RESULTS

Estimated drug costs over 16 weeks were $9,039 for EPO and $13,555 for DARB. During weeks 5-16, 85% of EPO patients and 73% of DARB patients were successfully treated, resulting in average cost-effectiveness ratios of $106 for EPO and $186 for DARB per one per cent of successfully treated patients. A 33% reduction in DARB WAC was required to achieve the same drug costs as for EPO.

CONCLUSIONS

Utilizing FDA-approved doses, EPO was found to result in lower drug costs and better treatment success when compared to DARB. Hence, EPO is a dominant alternative compared to DARB for the treatment of CIA. The analyses presented here are not without limitations. Specifically, although the studies were comparable, patients were ultimately drawn from different populations.

Association between intraocular pressure and budesonide inhalation therapy in asthmatic patients

BACKGROUND

The extent to which inhaled glucocorticoids increase the risk of intraocular pressure elevation has been controversial.

OBJECTIVE

The authors attempt to assess such risk attributable to budesonide, an inhaled glucocorticoid for asthma therapy.

METHODS

Data were pooled from four prospective, randomized, double-blind, parallel-group, placebo-controlled, multicenter clinical trials of 12 to 20 weeks in duration. One thousand two hundred and fifty-five patients, 6 to 70 years of age whose intraocular pressures (IOPs) were less than 23 mmHg at screening were randomized to receive placebo or inhaled budesonide at doses ranging from 100 to 800 microg, administered twice daily. Intraocular pressure was measured at screening and at the end of double-blind treatment. Intraocular change was compared between budesonide and placebo, accounting for the confounding effects of gender, race, age, history of diabetes, history of hypertension, clinical trial, systemic glucocorticoid use during the trials, ophthalmic glucocorticoid use during the trials, and prior oral glucocorticoid use.

RESULTS

No budesonide treatment effect on the IOP was evident either in the crude analysis or after adjustment for possible confounding factors. For patients exposed to budesonide at a total daily dose of 1600 microg for 20 weeks, there was no difference in IOP change compared with the placebo controls.

CONCLUSIONS

No association with an increased IOP was observed in asthmatic patients treated with budesonide at daily doses ranging from 200 to 1600 microg for durations of 12 to 20 weeks. The subgroup analysis, which focused on the highest dose and longer term therapy was reassuring, as was the overall result.

Descriptive epidemiology of acute liver enzyme abnormalities in the general population of central Massachusetts

OBJECTIVES

This study quantifies the incidence of liver enzyme abnormalities in the general population of central Massachusetts.

METHODS

Computerized data files from a health maintenance organization were used to ascertain potential subjects during the study period of 1 July 1992-30 June 1993. Medical records and laboratory tests results were reviewed to confirm the diagnoses.

RESULTS

The incidence rates were 40.6 cases per 100,000 persons per year for drug-associated liver enzyme abnormalities, 39.0 per 100,000 persons per year for liver enzyme abnormalities secondary to biliary pathologies, 25.2 per 100,000 persons per year for liver enzyme abnormalities secondary to mononucleosis, 25.2 per 100,000 persons per year for liver enzyme abnormalities of unknown aetiology, 15.4 per 100,000 persons per year for alcoholic liver enzyme abnormalities, 12.2 per 100,000 persons per year for liver malignancy, and 7.3 per 100,000 persons per year for viral hepatitis (HAV, HBV and HCV). Men were more commonly affected by alcoholic liver enzyme abnormalities and viral hepatitis, with respective incidence rates approximately 5 and 2 times higher than women. Liver enzyme abnormalities secondary to mononucleosis occurred predominantly between the ages of 15-24 years. In contrast, liver diseases secondary to biliary pathologies, liver malignancies and drug-associated liver enzyme abnormalities were found most frequently among the elderly.

CONCLUSION

Liver enzyme abnormalities occurred with a higher incidence in this general population than reported previously in selected patients. Drug-associated liver enzyme abnormality was the most common type. The magnitude of drug-associated liver enzyme abnormality could be much higher as an appreciable proportion of the liver cases of unknown aetiology are potentially drug-attributable.

Epidemiologic interpretation of artificial neural networks

Multilayer neural networks have been faulted for functioning as "black boxes" and for failing to assess the relative importance of the input factors. The aim of this paper is to illustrate how neural networks can classify individuals. The authors investigated the role of weights in the formation of neural networks' decision surfaces and decision regions. The data used were from a case-control study. Two strong determinants of case status were used as input "neurons." Zero, three, and five hidden neurons were used to explore the effect of the number of hidden neurons on the decision surfaces and regions. Mapping of input and output spaces revealed that three hidden neurons were insufficient to fully discriminate cases from controls. Five hidden neurons may be optimal, but at the cost of possible over-fitting. The more complex neural networks were very effective at defining regions of uniform risk in the plane of the initial covariates, and at assigning risk levels. The authors speculate that neural networks will prove useful in epidemiologic problems that require pattern recognition or complicated classification techniques, and that they will be unfavorable in problems that involve distinct effects of distinguishable predictors.

Prediction and cross-validation of neural networks versus logistic regression: using hepatic disorders as an example

The authors developed and cross-validated prediction models for newly diagnosed cases of liver disorders by using logistic regression and neural networks. Computerized files of health care encounters from the Fallon Community Health Plan were used to identify 1,674 subjects who had had liver-related health services between July 1, 1992, and June 30, 1993. A total of 219 subjects were confirmed by review of medical records as incident cases. The 1,674 subjects were randomly and evenly divided into training and test sets. The training set was used to derive prediction algorithms based solely on the automated data; the test set was used for cross-validation. The area under the Receiver Operating Characteristic curve for a neural network model was significantly larger than that for logistic regression in the training set (p = 0.04). However, the performance was statistically equivalent in the test set (p = 0.45). Despite its superior performance in the training set, the generalizability of the neural network model is limited. Logistic regression may therefore be preferred over neural network on the basis of its established advantages. More generalizable modeling techniques for neural networks may be necessary before they are practical for medical research.

The effectiveness of surgery on the treatment of acute spinal cord injury and its relation to pharmacological treatment

Using data from the Second National Acute Spinal Cord Injury Study (NASCIS II), the authors sought to characterize the role of surgery in the management of traumatic spinal cord injury and to examine the interaction between pharmacological treatment and surgery. Patients who did not undergo surgery had more severe spinal cord injuries initially than those who had surgery. However, no differences in neurological improvement at 1-year follow-up were found between those who underwent surgery and those who did not. The results suggest that either early surgery (< or = 25 hours after injury) or late surgery (> 200 hours) may be associated with increased neurological recovery, particularly motor function, but these results are equivocal. Surgery was not shown to interact with pharmacological treatments, indicating that the effect of drug treatment in NASCIS II, reported elsewhere, is not influenced by surgery. Other independent variables that best predicted improvement in motor score were age of 25 years or younger, incomplete injury, and lower baseline emergency department neurological scores. This study does not provide clinically relevant evidence concerning the efficacy of timing or the value of surgery in treating patients with spinal cord injuries. A randomized study on the timing and efficacy of spinal cord surgery is needed to obtain valid comparisons of the efficacy of surgical treatments.