Determinants of imminent fracture risk in postmenopausal women with osteoporosis

In elderly women with osteoporosis, prior fracture, low BMD, impaired physical functioning, poorer general health, and recent falls were all direct predictors of imminent (in next year) fracture risk. Prior fracture, older age, worse health, impaired cognitive functioning, and recent falls indirectly increased imminent risk by reducing physical functioning/general health.

INTRODUCTION

This study was designed to examine determinants of imminent risk of osteoporotic fracture (i.e., next 1-2 years) in postmenopausal women.

METHODS

This retrospective cohort study used data from Caucasian women age 65 or older with osteoporosis who participated in the observational Study of Osteoporotic Fractures (SOF). We examined potential direct and indirect predictors of hip and nonvertebral fractures in 1-year follow-up intervals including anthropometric measures, bone mineral density (T-score), fracture since age 50, physical function, cognition, medical conditions, recent (past year) falls, and lifestyle factors. Clinically related variables were grouped into constructs via factor analysis. These constructs and selected individual variables were incorporated into a theoretical structural equation model to evaluate factors that influence imminent risk.

RESULTS

Among 2261 patients, 19.4% had a nonvertebral fracture and 5.5% had a hip fracture within 1 year of a study visit between 1992 and 2008. Prior fracture, lower T-scores, lower physical functioning, and recent falls all directly increased 1-year risk of nonvertebral fracture. For both nonvertebral and hip fractures, prior fracture and recent falls influenced risk indirectly through general health, while cognition influenced risk via physical functioning. Age influenced both physical functioning and general health.

CONCLUSIONS

Several established risk factors for 10-year fracture risk also played a role in predicting imminent risk of fracture (e.g., T-scores, prior fracture), as did falls, cognition, physical functioning, and general health. Fracture risk assessments should also consider falls and fall risk factors as well as established bone-related risk factors in assessing imminent fracture risk.

Determinants of imminent fracture risk in postmenopausal women with osteoporosis

In elderly women with osteoporosis, prior fracture, low BMD, impaired physical functioning, poorer general health, and recent falls were all direct predictors of imminent (in next year) fracture risk. Prior fracture, older age, worse health, impaired cognitive functioning, and recent falls indirectly increased imminent risk by reducing physical functioning/general health.

INTRODUCTION

This study was designed to examine determinants of imminent risk of osteoporotic fracture (i.e., next 1-2 years) in postmenopausal women.

METHODS

This retrospective cohort study used data from Caucasian women age 65 or older with osteoporosis who participated in the observational Study of Osteoporotic Fractures (SOF). We examined potential direct and indirect predictors of hip and nonvertebral fractures in 1-year follow-up intervals including anthropometric measures, bone mineral density (T-score), fracture since age 50, physical function, cognition, medical conditions, recent (past year) falls, and lifestyle factors. Clinically related variables were grouped into constructs via factor analysis. These constructs and selected individual variables were incorporated into a theoretical structural equation model to evaluate factors that influence imminent risk.

RESULTS

Among 2261 patients, 19.4% had a nonvertebral fracture and 5.5% had a hip fracture within 1 year of a study visit between 1992 and 2008. Prior fracture, lower T-scores, lower physical functioning, and recent falls all directly increased 1-year risk of nonvertebral fracture. For both nonvertebral and hip fractures, prior fracture and recent falls influenced risk indirectly through general health, while cognition influenced risk via physical functioning. Age influenced both physical functioning and general health.

CONCLUSIONS

Several established risk factors for 10-year fracture risk also played a role in predicting imminent risk of fracture (e.g., T-scores, prior fracture), as did falls, cognition, physical functioning, and general health. Fracture risk assessments should also consider falls and fall risk factors as well as established bone-related risk factors in assessing imminent fracture risk.

Predictors of near-term fracture in osteoporotic women aged ≥65 years, based on data from the study of osteoporotic fractures

Using data from the Study of Osteoporotic Fractures (SOF), several clinical characteristics predictive of near-term (1-year) risk of hip and non-vertebral fracture among elderly osteoporotic women were identified, and a subset of those for hip fracture was incorporated into a risk assessment tool. Additional research is needed to validate study findings.

INTRODUCTION

While several risk factors are known to contribute to long-term fracture risk in women with osteoporosis, factors predicting fracture risk over a shorter time horizon, such as over a 1-year period, are less well-established.

METHODS

We utilized a repeated-observations design and data from the Study of Osteoporotic Fractures to identify factors contributing to near-term risk of hip fracture and any non-vertebral fracture, respectively, among osteoporotic women aged ≥65 years. Potential predictors of hip fracture and any non-vertebral fracture over the 1-year period subsequent to each qualifying SOF exam were examined using multivariable frailty models. Because the discriminative ability of the hip fracture model was acceptable, a corresponding risk-prediction tool was also developed.

RESULTS

Study population included 2499 women with osteoporosis, who contributed 6811 observations. Incidence of fracture in the 1-year period subsequent to each exam was 2.2% for hip fracture and 6.6% for any non-vertebral fracture. Independent predictors of hip fracture included low total hip T-score, prior fracture, and risk factors for falls (multivariable model c-statistic = 0.71 (95% CI 0.67-0.76)). Independent predictors of any non-vertebral fracture included age, total hip T-score, prior falls, prior fracture, walking speed, Parkinson's disease or stroke, and smoking (multivariable model c-statistic = 0.62 (0.59-0.65)).

CONCLUSIONS

Several clinical characteristics predictive of hip and non-vertebral fracture within a 1-year follow-up period among elderly women with osteoporosis were identified, and a subset of those for hip fracture was incorporated into a risk assessment tool. Assessment of these risk factors may help guide osteoporosis treatment choices by identifying patients in whom there is urgency to treat. Additional research is needed to validate the findings of this study and the accuracy of the risk assessment tool.

Adherence with bisphosphonate therapy and change in bone mineral density among women with osteoporosis or osteopenia in clinical practice

In clinical practice, adherence with bisphosphonate therapy varies greatly among women with osteoporosis or osteopenia. Our study suggests that better adherence with bisphosphonates confers tangible benefits in terms of graded increases in bone mineral density. Interventions to improve drug adherence should be an important component of disease management.

INTRODUCTION

In clinical trials, bisphosphonates have been found to increase bone mineral density (BMD) in women with osteoporosis or osteopenia. In clinical practice, where drug adherence is more variable, change in BMD with bisphosphonate therapy-overall and by level of adherence-is largely unknown.

METHODS

A retrospective cohort study was conducted at Henry Ford Health System (Detroit, MI, USA). Study subjects were women who had low BMD at the left total hip (T-score<-1.0), began oral bisphosphonate therapy, and had ≥1 BMD measurements at the left total hip≥6 months following treatment initiation. Change in BMD was calculated between the most recent pretreatment scan and the first follow-up scan. Adherence (i.e., medication possession ratio (MPR)) was measured from therapy initiation to the first follow-up scan.

RESULTS

Among 644 subjects, mean age was 66 years, pretreatment BMD was 0.73 g/cm2, and pretreatment T-score was -1.8. Over a mean follow-up of 27.1 months, mean MPR was 0.57 (95% CI, 0.54 and 0.59), and mean percentage change in BMD was 1.5% (1.1 and 1.9%). Within the MPR strata (five consecutive equi-intervals, from low (0-0.19) to high (0.80-1.0)), mean change in BMD was -0.8% (-1.6 and 0.1%), 0.7% (-0.3 and 1.7%), 2.1% (1.1 and 3.0%), 2.1% (1.4 and 2.9%), and 2.9% (2.3 and 3.5%), respectively. In adjusted analyses, percentage change in BMD was higher (by 1.4-3.4%, p<0.05 for all) in the highest four MPR intervals, respectively, versus MPR 0-0.19.

CONCLUSIONS

Among women with osteoporosis or osteopenia in clinical practice, better adherence with bisphosphonates appears to confer tangible benefits in terms of increases in BMD.

[Generalized anxiety disorder in primary care. Patterns of healthcare utilization in Germany]

BACKGROUND

Generalized Anxiety Disorder (GAD) has been described in community studies as a frequent and costly high utilizer group in the primary care sector. Administrative data supporting this observation are lacking so far.

METHODS

This paper reports utilization and prescription data of a nationally representative sample of over 900 primary care physicians, over 75 million prescriptions and 12-month utilization and prescription patterns of n = 3,340 GAD patients.These are compared to a matched control group without GAD, and without any anxiety or depressive disorder (n = 3,340).

RESULTS

GAD patients in comparison to the matched controls revealed: (1) 2-fold increased primary care, (2) almost 3-fold specialist referrals, (3) almost 2-fold increased overall prescription rates, and (4) 3.5-fold increased sick certificates. However, only 58.3% of GAD patients were treated with any psychotropic medication.

DISCUSSION

The data of this administrative-epidemiological cohort study support strongly the view that GAD ranks among the most costly high utilizer patient group in primary care in Germany. However, they are rarely treated according to evidence-based guidelines. The paper discusses these findings by suggesting that comorbid conditions might be a barrier for primary care physicians to initiate existing, more appropriate state of the art treatments.

Treatment of new-onset ulcerative colitis and ulcerative proctitis: a retrospective study

BACKGROUND

Although guidelines recommend use of oral 5-aminosalicylates (5-ASAs) as first-line therapy in patients with mild to moderate ulcerative colitis (UC) and ulcerative proctitis (UP) and steroids with or without 5-ASAs in those more severely ill, little is known about how UC and UP are actually treated.

AIM

To document treatment of new-onset UC and UP in routine clinical practice.

METHODS

Using a large US health insurance database, we identified all persons with new-onset UC or UP between 1 January 2005 and 31 December 2007, based on: (i) initial receipt of an oral 5-ASA, mesalazine (mesalamine) suppository, 5-ASA enema, steroid, antimetabolite, budesonide or TNF inhibitor; (ii) sigmoidoscopy/colonoscopy in prior 30 days resulting in a new diagnosis of UC or UP and (iii) no prior encounters for Crohn's disease. We examined patterns of pharmacotherapy over 1 year.

RESULTS

We identified 1516 UC patients and 636 UP patients who met study entry criteria. In UC, initial therapies most frequently used were oral 5-ASAs (53% of patients), oral 5-ASAs and systemic steroids (12%), systemic steroids (8%) and mesalazine suppositories (6%); in UP, mesalazine suppositories (42%) and oral 5-ASAs (19%) were most often used, followed by combination therapy (14%), mesalazine enema (11%) and rectal steroids (10%). Few patients received maintenance therapy, and there was limited use of antimetabolites and biological agents.

CONCLUSIONS

Oral 5-ASAs and systemic steroids are the mainstay of treatment in patients with new-onset ulcerative colitis; in those with new-onset ulcerative proctitis, it is mesalazine suppositories. Care of these patients appears consistent with treatment guidelines.

STUDIES ON THE SONIC TREATMENT OF TOBACCO MOSAIC VIRUS

Centrifugally purified samples of tobacco mosaic virus were subjected to intense sound vibrations of 9,000 cycles per second for 0, 2, 8, 16, 32, and 64 minutes. The viscosity and stream birefringence of the samples decreased with time of sonic treatment, but no chemical changes were found. Electron micrographs of the samples show that the particles are broken perpendicular to their long axis. In the untreated sample 62 per cent of the particles are about 280 mmicro in length. As sonic treatment continued, the number of particles of this length decreased exponentially with time, the number half this length increased and then decreased, and the number of quarter length particles subsequently increased and then decreased. The biological activity of the samples, as determined by the half leaf lesion method, decreased exponentially with time of sonic treatment with a rate constant given by k = 0.13 min.(-1). A correlation exists between the size distributions and biological activity and shows that only the particles of length 280 mmicro are the biologically active units. Tobacco mosaic virus particles can be made to aggregate end-to-end when the material is heated at its isoelectric point and reheated after being brought back to pH 7. Material which was not sonic treated and was made to aggregate showed reduced biological activity, but the activity was increased when the aggregated material was subjected to strong mechanical stirring. Material which was sonic treated for 32 minutes and which was made to aggregate showed the same biological activity as the material which was sonic treated but not aggregated.

Why is the mechanical efficiency of F(1)-ATPase so high?

The experimentally measured mechanical efficiency of the F(1)-ATPase under viscous loading is nearly 100%, far higher than any other hydrolysis-driven molecular motor (Yasuda et al., 1998). Here we give a molecular explanation for this remarkable property.

Cost of neutropenic complications of chemotherapy

BACKGROUND

Cost of neutropenic complications of myelosuppressive chemotherapy has been reported to be substantial. Prior research, however, has focused on initial hospitalization only and has failed to account for follow-on care.

PATIENTS AND METHODS

Using a US health-care claims database, all adult cancer patients who received a course of chemotherapy were identified. For each such patient, each unique cycle of chemotherapy within the course and each occurrence of neutropenic complications within these cycles were characterized. Patients developing neutropenic complications in a given cycle (neutropenia patients), starting with the first, were matched (1:1) to those who did not develop neutropenic complications in that cycle (comparison patients), and health-care costs (i.e. expenditures) were tallied for each matched pair.

RESULTS

Neutropenia patients (n = 373) and comparison patients were similar in terms of baseline characteristics. Costs of neutropenia-related care were $12,397 (95% confidence interval $10,274-$14,754) higher for neutropenia versus comparison patients [$14,407 ($12,357-$16,743) versus $2010 ($1490-$2553)]. Among neutropenia patients, mean cost of initial hospitalization for neutropenic complications was $7813 ($6537-$9379); cost of all subsequent neutropenia-related care averaged $6594 ($5217-$8272).

CONCLUSIONS

Neutropenic complications of myelosuppressive chemotherapy are costly. Prior research focusing on initial hospitalization only may have underestimated the cost of these complications by as much as 40%.

Characteristics and healthcare costs of patients with fibromyalgia syndrome

PURPOSE

To examine the characteristics and healthcare costs of fibromyalgia syndrome (FMS) patients in clinical practice.

MATERIALS AND METHODS

Using a US health-insurance database, we identified all patients, aged > or = 18 years, with any healthcare encounters for FMS (ICD-9-CM diagnosis code 729.1) in each year of the 3-year period, 1 July 2002 to 30 June 2005. A comparison group was then constituted, consisting of randomly selected patients without any healthcare encounters for FMS during this 3-year period. Comparison group patients were matched to FMS patients based on age and sex. Characteristics and healthcare costs of FMS patients and comparison group patients were then examined over the 1-year period, 1 July 2004 to 30 June 2005 (the most recent year for which data were available at the time of the study).

RESULTS

The study sample consisted of 33,176 FMS patients and an identical number in the comparison group. Mean age was 46 years, and 75% were women. FMS patients were more likely to have various comorbidities, including painful neuropathies (23% vs. 3% for comparison group), anxiety (5% vs. 1%), and depression (12% vs. 3%) (all p < 0.001); they also were more likely to have used pain-related pharmacotherapy (65% vs. 34% for comparison group; p < 0.001). Mean (SD) total healthcare costs over 12 months were about three times higher among FMS patients [$9573 ($20,135) vs. $3291 ($13,643); p < 0.001]; median costs were fivefold higher ($4247 vs. $822; p < 0.001).

CONCLUSIONS

Patients with FMS have comparatively high levels of comorbidities and high levels of healthcare utilization and cost.

Risk of chronic kidney disease in hypertensive patients with other metabolic conditions

Using a retrospective cohort design and electronic medical records, we examined chronic kidney disease (CKD) risk over a 6-year period among hypertensive patients in relation to the presence of diabetes, hyperlipidaemia and/or high body mass index. After adjusting for age, sex, smoking status and baseline glomerular filtration rate (GFR), hypertensive patients without other metabolic risk factors had a relative risk of CKD (versus normotensive patients) of 2.0 (95% CI 1.8-2.2); hypertensive patients with other metabolic conditions had adjusted relative risks ranging from 2.4 to 2.6 for those without comorbid diabetes, and from 3.3 to 5.5 for those with comorbid diabetes. Our study thus confirms prior research demonstrating elevated CKD risk in hypertensive patients, and suggests that this risk varies substantially in relation to other metabolic conditions, especially diabetes.

Oral mucositis is associated with increased resource use among patients receiving treatment for cancers of the head and neck

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Background: Oral mucositis (OM) is the oral manifestation of mucosal injury (MUI), and is a common, bothersome, and treatment-interrupting toxicity of chemoradiation therapy for squamous cell cancers (SCC) of the head and neck. Retrospective studies have reported that OM increases healthcare resource use. We present interim results of an international, multicenter, prospective study undertaken to characterize the clinical and economic burden of OM in patients with cancers of the oral cavity (OC), oropharynx (OP), larynx (L) and hypopharynx (HP). Methods: Patients (pts) with histologically proven SCC of the designated anatomical sites, whose planned treatment included full-cycle conventional or intensity modulated (IM) radiation therapy (RT) with or without chemotherapy, were enrolled at least one week prior to the start of treatment. Pts completed the Oral Mucositis Daily Questionnaire (OMDQ), a validated questionnaire developed to document patient-reported symptoms of OM and MUI including mouth and throat soreness (MTS), at baseline and daily throughout RT. MTS was assessed using a 5-point numeric rating scale, ranging from 0 (“no soreness”) to 4 (“extreme soreness”). Results: Of the first 61 pts to complete RT, 72% had cancers of the OC or OP, 49% received IMRT with concomitant chemotherapy, and 68% were male. 95% of pts reported OM symptoms (MTS>0); 80% had one or more scores =2. Pts with OC or OP cancers reported more symptoms than those with L or HP tumors (mean maximum score: 3.3 vs 2.8; p= 0.12). MTS scores were positively related to levels of resource use. Conclusions: Symptoms of radiation-induced OM are positively correlated with levels of resource utilization in patients with head and neck cancers.

No significant financial relationships to disclose.

[Table: see text]

Healthcare (HC) utilization and costs in patients (pts) with newly diagnosed metastatic thyroid cancer (mTC)

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Background: mTC is relatively rare and little is known about treatment patterns or HC costs in patients with newly diagnosed disease. Methods: Retrospective longitudinal cohort study. Using a large (∼14 million covered lives) US health-insurance claims database, we identified a cohort of pts with diagnoses of thyroid cancer (ICD-9-CM diagnosis codes 193.XX) and distant metastatic disease (197.XX-198.XX) between 1/1/2003 and 12/31/2005 (“study period”); the date of first mention of metastatic disease was designated the “index date”. All pts were required to be =18 years of age as of their index date and to have been continuously enrolled in the database for =6 months prior to this date. Pts were followed from their index date until health plan disenrollment (for any reason) or end of the study period, whichever occurred first. Utilization of HC services and costs (total reimbursed amount including pt liability) were then examined during each quarter of follow-up (eg, first 3 months of follow-up=Q1). Results: 183 pts met all study entry criteria. Mean (±SD) age was 51.5 (11.8) years; mean duration of follow-up was 344 days (median=275 days). Most common management/treatment strategies during Q1 included: imaging [eg, US/CT of the neck (49.7%)], thyroglobulin/thyroglobulin antibody testing (25.7%); radiation therapy (23.0%); I131 therapy (19.1%); thyroid surgery (12.6%); chemotherapy (10.9%); lymphadenectomy (8.7%); and bisphosphonate therapy (3.8%). In addition, during Q1, pts averaged 9.5 office visits (95% CI, 8.2, 10.9) and 0.6 hospitalizations (95% CI, 0.5, 0.7); for pts hospitalized during Q1, average length of stay was 6.6 (95% CI, 4.9, 8.4). Costs during the first 2 years of follow-up are presented in the table ; inpt care represented 43% of total HC costs. Conclusions: Many different treatment modalities are used in pts with newly diagnosed mTC; the cost of such care is substantial.

[Table: see text]

[Table: see text]

Patient-reported burden of mucosal injury (MUI): Comparison of clinician-rated MUI and patient-reported outcomes

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Background: Patient (pt) reported outcome (PROs) tools identify MUI and its impact on functional and subjective outcomes. Among outpts, PRO tools are attractive because opportunities for direct assessment are limited, but agreement between PRO tools and objective MUI measures has not been uniform. We prospectively compared an objective MUI score and 3 previously validated PRO tools. Method: The Triad Burden of Illness study is an international, 41-center, prospective study of the risk and outcomes of radiation and chemotherapy-induced MUI. At baseline and during chemoradiation therapy (CRT), pts with larynx (L), hypopharynx (H), or non-small cell lung cancers (NSCLC) completed a daily MUI symptom tool (OMDQ) and 2 weekly PRO tools (FACT-E quality of life, FACIT- Fatigue). Clinicians examined pts twice weekly and scored MUI (WHO scale). In this interim analysis, we used random effects linear regression to compare clinician and pt ratings and t-tests to compare PRO scores in pts with and without severe MUI. Result: To date, 29 pts have completed =2 paired assessments; 23 (79%) had L or H cancers. Ulcerative MUI (WHO = 2) was more common among L/H than NSCLC pts (39% vs 17%). Pt-rated MUI predicted clinician-rated MUI (p = 0.001). FACT-E and FACIT-F scores were significantly lower (worse) among pts with clinician-rated ulcerative MUI than pts without and among pts with pt-rated severe MUI symptoms (OMDQ= 2) than pts without. Differences were largest in the subscales for physical and functional wellbeing and esophageal symptom special concerns. Conclusion: PRO tools estimate the burden of CRT-induced MUI in outpts with L/H or NCSL cancers. MUI appears to be associated with significantly poorer quality of life, functional status, and symptom scores. 1- 9 p <0.01; 10p = 0.06.

[Table: see text]

[Table: see text]

Compliance with osteoporosis drug therapy and risk of fracture

INTRODUCTION

Patient compliance with osteoporosis drug therapy is often poor in clinical practice and may be associated with higher risk of fracture.

METHODS

A nested case-control study was undertaken using a US health insurance claims database. The source population included all women aged >or=45 years who began drug therapy for osteoporosis. Cases consisted of those who experienced an osteoporosis-related fracture; they were matched to controls without osteoporosis-related fracture. Compliance with osteoporosis drug treatment was assessed in terms of the number of therapy-days received and medication possession ratio (MPR). Conditional logistic regression was employed to examine the relationship between compliance and fracture risk.

RESULTS

A total of 453 women with osteoporosis-related fracture were identified and matched to 2,160 controls. Fracture risk was significantly lower for patients with >180 days of therapy [181-360 days: odds ratio (OR) = 0.70, 95% CI = 0.49-0.99; >360 days: OR = 0.65, 95% CI = 0.43-0.99) versus those with <or=30 days. Risk was also lower for patients with MPR >or=90% (OR = 0.70, 95% CI = 0.52-0.93) versus those with MPR <30%. Fracture risk decreased as compliance increased (p(trend) < 0.05).

CONCLUSION

Among women initiating drug therapy for osteoporosis, better compliance is associated with reduced risk of fracture.

Risk of diabetes in a real-world setting among patients initiating antihypertensive therapy with valsartan or amlodipine

In the Valsartan Antihypertensive Long-Term Use Evaluation (VALUE) trial, the risk of new-onset diabetes was reported to be 23% lower among patients initiating therapy with valsartan versus amlodipine. The objective of our study was to examine whether this finding is generalizable to 'real-world' clinical practice. A retrospective cohort design and a large US health insurance database were employed for analyses. Study subjects included all hypertensive patients, aged >or=35 years, who were free from diabetes and who initiated treatment with valsartan (n=9999) or amlodipine (n=18 698) between January 1999 and March 2005. Unadjusted absolute risks of diabetes were 21.4 (95% confidence interval (CI) 18.9-24.3) and 26.3 (95% CI 24.3-28.3) per 1000 patient-years for valsartan and amlodipine, respectively; the corresponding relative risk (RR) for valsartan was 0.82 (95% CI 0.70-0.94). Multivariate analyses - controlling for age, sex, presence of hypercholesterolemia, cardiovascular disease and kidney disease, and pretreatment medical care expenditures - yielded similar results (RR=0.79, 95% CI 0.68-0.92). Our study thus corroborates the finding from VALUE that diabetes risk is lower for patients who receive valsartan versus amlodipine, and extends this finding to a 'real-world' setting.

Cost of chemotherapy-related febrile neutropenia

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Background: Febrile neutropenia (FN) is a serious complication of myelosuppressive chemotherapy that typically necessitates hospitalization. While the costs of FN have been reported to be substantial, previous studies may have underestimated these costs due to failure to account for follow-on care. Methods: A retrospective cohort study was undertaken using a US healthcare claims database. The source population included adult cancer patients who received a course of chemotherapy between 2001 and 2003. For each such patient, each unique cycle of chemotherapy was identified, and patients who developed FN within these cycles were further identified based on hospitalization for neutropenia, fever, and/or infection. Patients with FN in a given cycle (“cases”), starting with the first, were matched–on tumor type, number of cycles, chemotherapy characteristics, and propensity score–to those not experiencing FN in that cycle (“controls”), regardless of occurrence of FN in subsequent cycles; once matched, patients were removed from their respective pools. FN-related healthcare charges–including inpatient, outpatient, and drug treatment for neutropenia, fever, and infection–were tallied for each such pair of patients from the cycle day on which cases developed FN through the last chemotherapy cycle. Healthcare charges were used as a proxy for costs, as the latter were unavailable. Results are reported as means and 95% confidence intervals. Results: The study population consisted of 746 patients; 38% had breast cancer, 21% had lung cancer, and 11% had non-Hodgkin’s lymphoma. Cases and controls were similar in terms of baseline characteristics. FN-related charges totaled $40,928 (95%CI $28,783-$62,586) among cases versus $3,933 ($2,890-$5,119) for controls, a difference of $36,995 ($25,283-$58,776). Non-FN-related charges were similar in the two groups ($32,774 [$28,587-$36,061] vs. $32,253 [$29,248-$36,066]). Care subsequent to initial hospitalization accounted for $9,872 (or 27%) of the higher FN-related charges among cases. Conclusions: Costs of care during chemotherapy are twofold higher among patients who develop FN; follow-on care represents more than one-quarter of the difference.

[Table: see text]

Use of antiepileptics and tricyclic antidepressants in cancer patients with neuropathic pain

Using a large US health insurance claims database, we identified all persons aged > or =18 years with > or =2 medical encounters with diagnoses of cancer and > or =2 medical encounters with diagnoses of painful neuropathies in calendar year (CY) 2000; persons with seizure disorders or depression were excluded. We then examined the use of antiepileptics (AEDs), tricyclic antidepressants (TCAs) and other pain-related pharmacotherapy among these selected persons, as proxied by pharmacy dispenses. A total of 956 persons were identified who met all entry criteria; 17% received AEDs in CY2000 and 14% received TCAs. Gabapentin was the most widely used AED (92% of all AED patients); amitriptyline was the most widely used TCA (79% of all TCA patients). Patients who received AEDs and/or TCAs were similar in age, gender and the presence of metastases to those who had not received these medications; they were more likely to have received other pain-related therapies, however, including short-acting opioids (73% vs. 53%; P < 0.01) and long-acting opioids (23% vs. 8%; P < 0.01). Use of AEDs and TCAs appears to be relatively low among cancer patients with painful neuropathies. Further research is needed to better understand reasons for this finding, as well as its potential implications for pain management in this patient population.

Compliance with drug therapy for postmenopausal osteoporosis

INTRODUCTION

Patient compliance with pharmacotherapy for osteoporosis is typically poor in clinical practice; less frequent dosing with bisphosphonates may improve compliance.

METHODS

Using data from 49 US health plans, we identified all women aged >/=45 years with osteoporosis who initiated therapy with a bisphosphonate, calcitonin, estrogen, or raloxifene. Compliance was examined alternatively in terms of incidence of adherence failure (medication days <80% of possible) and persistence failure (gap in therapy >/=90 days), and was compared across treatment groups using Kaplan-Meier methods and Cox proportional hazards models.

RESULTS

The study population included 18,822 women, 48% of whom initiated weekly bisphosphonate therapy. Overall risk of adherence failure was 47% at 3 months, 70% at 1 year, and 84% at 3 years. Risk of persistence failure was 47% at 1 year, and 77% at 3 years. In multivariate analyses, risk of adherence failure was higher for calcitonin (hazard ratio=2.7 vs weekly bisphosphonate therapy, p<0.01), but comparable for all other therapies. Relative risks of persistence failure were generally similar.

CONCLUSIONS

Approximately three-quarters of women who initiate osteoporosis drug therapy are non-adherent with treatment within 12 months, and almost 50% have discontinued such therapy by this time. Compliance with weekly bisphosphonate therapy is generally no better than that with osteoporosis medications requiring more frequent dosing.

Effects of weight gain on medical care costs

OBJECTIVE

To examine in middle-aged adults the effect of medical care costs of large, rapid weight gain compared to weight maintenance.

DESIGN

: Retrospective cohort study for a 3-y time period.

SETTING AND PARTICIPANTS

Population-based sample (N=15174) of men and women members of a large managed care organization, aged 35-65 y, with a body mass index (BMI) >25 kg/m(2) at baseline. Health-care utilization and costs were measured at baseline and over the 3-y follow-up period.

RESULTS

Mean age at baseline was 49.7 y and mean BMI was 31.5 kg/m(2). During the 3-y follow-up period, 40.8% were classified as weight maintainers (+/-4 pounds), 45.3% gained 5-19 pounds, and 13.9% gained >/=20 pounds. A weight gain of >/=20 pounds was significantly associated with increased total medical care costs in all subgroups evaluated. Among all subjects, for those who gained >/=20 pounds compared to those who maintained weight, the adjusted 3-y increase in costs was 561 dollars. Among the subgroup with baseline comorbidities, the adjusted 3-y change in total medical care costs was 711 dollars. Multivariate analyses showed no significant differences between those who gained 5-19 pounds and those who maintained weight. Baseline BMI and comorbidities were also significant predictors of change in medical care costs, independent of weight gain.

CONCLUSION

A large 3-y weight gain (>/=20 lb) in middle-aged overweight and obese adults is associated with a correspondingly larger increase in total medical care costs compared to weight maintainers. The prevention of large weight gains holds promise for significantly reducing future medical care costs. Future studies should examine the causes of rapid weight gain and evaluate approaches to prevent and reverse such weight gain.

Development and validation of a measure of disease-specific quality of life in young children with haemophilia

No disease-specific tool for measuring health-related quality of life (HRQL), an important outcome when assessing medical treatment, has been developed for children with haemophilia. The goal of this study was to develop a parent-administered questionnaire for evaluating quality of life (QOL) in paediatric haemophilia patients between 2 and 6 years of age. After interviewing physicians (5), nurses (5) and parents (10) of children with haemophilia aged between 2 and 6 years, 92 questions were developed and pilot-tested with parents (44) of children with haemophilia to create a 39-question instrument that assessed somatic symptoms, physical functioning, sleep disturbance, stigma, social functioning, fear/resentment, mood/behaviour, restrictions, treatment upset, haemophilia concern and energy level. Reliability and validity were evaluated with 103 parents of children with haemophilia and parents of 249 age- and gender-matched healthy children. Estimates of scale reliability (internal consistency) for eight multi-item scales ranged from 0.73 to 0.94. Results showed construct validity (correlations with age, severity of haemophilia, treatment type, days absent and days confined to bed) and correlated with two general, paediatric quality-of-life instruments (Impact on Family Scale and Functional Status II). Discriminant validity was demonstrated by comparing scores between patients receiving/not receiving prophylactic therapy and between haemophilia patients and healthy controls. This disease-specific HRQL measure should be of use in clinical trials and general practice to better understand disease and treatment impacts in young children with haemophilia.

Pattern formation and traveling waves in myxobacteria: theory and modeling

Recent experiments have provided new quantitative measurements of the rippling phenomenon in fields of developing myxobacteria cells. These measurements have enabled us to develop a mathematical model for the ripple phenomenon on the basis of the biochemistry of the C-signaling system, whereby individuals signal by direct cell contact. The model quantitatively reproduces all of the experimental observations and illustrates how intracellular dynamics, contact-mediated intercellular communication, and cell motility can coordinate to produce collective behavior. This pattern of waves is qualitatively different from that observed in other social organisms, especially Dictyostelium discoideum, which depend on diffusible morphogens.

Venous thromboembolism following major orthopedic surgery: review of epidemiology and economics

The epidemiology and economics of venous thromboembolism (VTE) associated with hip and knee arthroplasty and surgical repair of hip fracture are reviewed. In the 1960s and 1970s, prior to the widespread use of prophylaxis, the risk of VTE following major orthopedic surgery was substantial. The risk of fatal pulmonary embolism (PE) following hip fracture repair may have been as high as 7.5%. With improvements in surgical and anesthetic techniques and the use of anticoagulant prophylaxis, these risks have decreased significantly for most patients. Current risks after hip and knee arthroplasty appear to be about 2.5% for deep vein thrombosis, 1% for nonfatal PE, and a few tenths of 1% for fatal PE over a three-month period following surgery. Because of the traumatic nature of the injury, delays in getting to surgery, and their more advanced age and poorer overall health, hip fracture patients appear to have a greater risk of postoperative VTE, but data are lacking for a reliable estimate of current risk. The cost of VTE after major orthopedic surgery includes initial therapy (the chief component), follow-up care, and the expected costs of major hemorrhage (due to anticoagulation), recurrent VTE, and postthrombotic syndrome. The total cost per patient of such care is approximately $11,600. The risk of VTE after surgery to replace hip and knee joints and repair hip fracture is far lower today than in the 1960s and 1970s, but the cost of treating VTE remains high: an estimated $11,600 per patient, including hospitalization costs.

Cost-effectiveness results from the US Carvedilol Heart Failure Trials Program

OBJECTIVE

To evaluate the cost-effectiveness of carvedilol, a beta-blocker that is approved for use in the US for the treatment of heart failure, based on data from Phase III clinical trials.

METHODS

We conducted an economic evaluation alongside the US Carvedilol Heart Failure Trials Program, which consisted of four concurrent, randomized, double-blind, placebo-controlled clinical trials; the mean duration of follow-up across these four trials was 6.5 months (the program was terminated prematurely based on a finding of a 65% mortality benefit). Using data from these trials, we examined the cost-effectiveness of carvedilol in terms of the estimated cost per death averted among patients randomized to such therapy versus those receiving placebo. Attention was focused on the cost of carvediol therapy plus the cost of cardiovascular-related inpatient care. Costs of care were estimated by combining infomation on healthcare utilization from the clinical trials with secondary sources of cost data.

RESULTS

Patients randomized to receive carvedilol had lower mean +/- SD estimated costs of cardiovascular-related inpatient care over 6.5 months compared with those receiving placebo ($1912 +/- $7595 vs. $4463 +/- $20,565, respectively). As mortality alsowas lower among carvedilol patients, the estimated cost per death averted was negative. The probability that carvedilol would both increase survival and decrease costs of cardiovascular-related care over a 6.5-month period was estimated to be 0.98.

CONCLUSIONS

Data from the US Carvedilol Heart Failure Trials Program indicate that carvedilol reduces mortality in patients with heart failure; our study suggests that it also may be cost-saving over a period of approximately six months.

The physics of molecular motors

Molecular motors convert chemical energy into mechanical force and movement. Operating at energies just above those of the thermal bath, these motors experience large fluctuations, and their physical description must be necessarily stochastic. Here, motor operation is described as a biased diffusion on a potential energy surface defined by the interactions of the motor with its track and its fuel. These ideas are illustrated with a model of the rotary movement of the F(o) motor.

Influence of carvedilol on hospitalizations in heart failure: incidence, resource utilization and costs. U.S. Carvedilol Heart Failure Study Group

BACKGROUND

Carvedilol reduces disease progression in heart failure, but to our knowledge, its effects on hospitalizations and costs have not been evaluated.

OBJECTIVES

We examined the effects on hospitalization frequency and costs in the U.S. Carvedilol Heart Failure Trials Program. This program consisted of four concurrent, multicenter, double-blind, placebo-controlled studies involving 1,094 patients with New York Heart Association class II to IV heart failure, which treated patients with placebo or carvedilol for up to 15 months (median, 6.5 months).

METHODS

Detailed resource utilization data were collected for all hospitalizations occurring between randomization and the end of follow-up. In-patient care costs were estimated based on observed levels of resource use.

RESULTS

Compared with placebo, carvedilol reduced the risk of hospitalization for any reason by 29% (p = 0.009), cardiovascular hospitalizations by 28% (p = 0.034) and heart failure hospitalizations by 38% (p = 0.041). Carvedilol also decreased the mean number of hospitalizations per patient (for cardiovascular reasons 30% [p = 0.02], for heart failure 53% [p = 0.03]). Among hospitalized patients, carvedilol reduced severity of illness during hospital admission, as reflected by shorter length of stay and less frequent use of intensive care. For heart failure hospital admissions, carvedilol decreased mean length of stay by 37% (p = 0.03) and mean number of intensive care unit/coronary care unit days by 83% (p = 0.001), with similar effects on cardiovascular admissions. As a result, estimated inpatient care costs with carvedilol were 57% lower for cardiovascular admissions (p = 0.016) and 81% lower for heart failure admissions (p = 0.022).

CONCLUSIONS

Carvedilol added to angiotensin-converting enzyme inhibition reduces hospitalization risk as well as severity of illness and resource utilization during admission in patients with chronic heart failure.

Oral mucositis and the clinical and economic outcomes of hematopoietic stem-cell transplantation

PURPOSE

To explore the relationship between oral mucositis and selected clinical and economic outcomes in blood and marrow transplant patients.

PATIENTS AND METHODS

Subjects consisted of 92 transplant patients from eight centers who participated in a multinational pilot study of a new oral mucositis scoring system (Oral Mucositis Assessment Scale [OMAS]). In the pilot study, patients were evaluated for erythema and ulceration/pseudomembrane formation beginning on the first day of conditioning and continuing for 28 days. We examined the relationship between patients' peak OMAS scores and days with fever (body temperature > 38.0 degrees C), the occurrence of significant infection, days of total parenteral nutrition (TPN), and days of injectable narcotic therapy (all over 28 days), days in hospital (over 60 days), total hospital charges for the index admission, and vital status at 100 days.

RESULTS

Patients' peak OMAS scores spanned the full range of possible values (0 to 5) and were significantly (P <.05) correlated with all of the outcomes of interest except days with fever (P =.21). In analyses controlling for type of graft (autologous v allogeneic) and study center, a 1-point increase in peak OMAS score was associated with (1) 1.0 additional day with fever (P <.01), (2) a 2.1-fold increase in risk of significant infection (P <.01), (3) 2.7 additional days of TPN (P <.0001), (4) 2.6 additional days of injectable narcotic therapy (P <.0001), (5) 2.6 additional days in hospital (P <.01), (6) $25,405 in additional hospital charges (P <.0001), and (7) a 3.9-fold increase in 100-day mortality risk (P <.01). Mean hospital charges were $42,749 higher among patients with evidence of ulceration compared with those without (P =.06).

CONCLUSION

Oral mucositis is associated with significantly worse clinical and economic outcomes in blood and marrow transplantation.

A randomized trial of controlled-release oxycodone during inpatient rehabilitation following unilateral total knee arthroplasty

BACKGROUND

Reliance on "as-needed" analgesia following total knee arthroplasty may lead to inadequate control of pain and delayed recovery of function. Preemptive use of controlled-release opioids may improve pain control, accelerate recovery, and reduce the need for inpatient rehabilitative services. This study was designed to determine whether controlled-release opioids enhance post-arthroplasty pain control and facilitate functional recovery during rehabilitation.

METHODS

Fifty-nine patients admitted for inpatient rehabilitation following unilateral total knee arthroplasty were randomized to receive OxyContin (controlled-release oxycodone) (twenty-nine patients) or a placebo (thirty patients) every twelve hours. Both groups could receive on-request, immediate-release oxycodone (5 mg every four hours). The dose of study medication was increased on the basis of the frequency of requests for immediate-release oxycodone. Measures of interest included pain ratings as determined with a visual-analog scale, changes in the range of motion of the knee and quadriceps strength, and improvements in selected Functional Independence Measure scores during the first eight physical therapy sessions. The duration of the hospital stay for rehabilitation also was compared between the two groups.

RESULTS

Baseline demographic, clinical, and functional characteristics were similar between the OxyContin and placebo groups. Compared with the placebo group, the patients who received OxyContin reported significantly less pain as well as significantly greater range of motion of the knee (passive motion, p = 0.036; active motion, p< 0.001) and quadriceps strength (p = 0.001) by the eighth physical therapy session. The patients who received OxyContin also were discharged from the rehabilitation hospital at an average of 2.3 days earlier than the patients in the placebo group (p = 0.013).

CONCLUSIONS

Preemptive use of controlled-release oxycodone during rehabilitation following total knee arthroplasty leads to improved pain control, more rapid functional recovery, and a reduced need for inpatient rehabilitative services.

Statistical thermodynamics of membrane bending-mediated protein-protein attractions

Highly wedge-shaped integral membrane proteins, or membrane-adsorbed proteins can induce long-ranged deformations. The strain in the surrounding bilayer creates relatively long-ranged forces that contribute to interactions with nearby proteins. In contrast, to direct short-ranged interactions such as van der Waal's, hydrophobic, or electrostatic interactions, both local membrane Gaussian curvature and protein ellipticity can induce forces acting at distances of up to a few times their typical radii. These forces can be attractive or repulsive, depending on the proteins' shape, height, contact angle with the bilayer, and a pre-existing local membrane curvature. Although interaction energies are not pairwise additive, for sufficiently low protein density, thermodynamic properties depend only upon pair interactions. Here, we compute pair interaction potentials and entropic contributions to the two-dimensional osmotic pressure of a collection of noncircular proteins. For flat membranes, bending rigidities of approximately 100k(B)T, moderate ellipticities, and large contact angle proteins, we find thermally averaged attractive interactions of order k(B)T. These interactions may play an important role in the intermediate stages of protein aggregation. Numerous biological processes where membrane bending-mediated interactions may be relevant are cited, and possible experiments are discussed.

Body mass index and future healthcare costs: a retrospective cohort study

OBJECTIVE

To assess the relationship between body mass index (BMI) and future healthcare costs.

RESEARCH METHODS AND PROCEDURES

We undertook a retrospective cohort study of the relationship between obesity and future healthcare costs at Kaiser Permanente Northwest Division, a large health maintenance organization in Portland, Oregon. Study subjects (n = 1286) consisted of persons who responded to a 1990 health survey that was mailed to a random sample of adult Kaiser Permanente Northwest Division members who were 35 to 64 years of age; had a BMI > or = 20 kg/m(2) (based on self-reported height and weight); did not smoke cigarettes; and did not have a history of coronary heart disease, stroke, human immunodeficiency virus, or cancer. Subjects were stratified according to their BMI in 1990 (20 to 24.9, 25 to 29.9, and > or = 30 kg/m(2); n = 545, 474, and 367, respectively). We then tallied their costs (in 1998 US dollars) for all inpatient care, outpatient services, and prescription drugs over a 9-year period (1990 through 1998).

RESULTS

For persons with BMIs of 20 to 24.9 kg/m(2), mean (+/-SE) annual costs of prescription drugs, outpatient services, inpatient care, and all medical care averaged $261 (+/-18), $848 (+/-59), $532 (+/-85), and $1631 (+/-120), respectively, over the study period. Cost ratios (95% confidence intervals) for persons with BMIs of 25 to 29.9 kg/m(2) and > or = 30 kg/m(2), respectively, were 1.37 (1.12 to 1.66) and 2.05 (1.62 to 2.55) for prescription drugs, 0.96 (0.83 to 1.13) and 1.14 (0.97 to 1.37) for outpatient services, 1.20 (0.81 to 1.86) and 1.38 (0.91 to 2.14) for inpatient care, and 1.10 (0.91 to 1.35) and 1.36 (1.11 to 1.68) for all medical care.

DISCUSSION

Future healthcare costs are higher for persons who are overweight, especially those with BMIs > or = 30 kg/m(2).