Michael J. Goodman

Inhibitors of hydroxymethylglutaryl-coenzyme A reductase and risk of fracture among older women

BACKGROUND Inhibitors of hydroxymethylglutaryl-coenzyme A reductase (statins) increase new bone formation in rodents and in human cells in vitro. Statin use is associated with increased bone mineral density of the femoral neck. We undertook a population-based case-control study at six health-maintenance organisations in the USA to investigate further the relation between statin use and fracture risk among older women. METHODS We investigated women aged 60 years or older. Exposure, outcome, and confounder information was obtained from automated claims and pharmacy data from October, 1994, to September, 1997. Cases had an incident diagnosis of non-pathological fracture of the hip, humerus, distal tibia, wrist, or vertebrae between October, 1996, and September, 1997. Controls had no fracture during this period. We excluded women with records of dispensing of drugs to treat osteoporosis. FINDINGS There were 928 cases and 2747 controls. Compared with women who had no record of statin dispensing during the previous 2 years, women with 13 or more statin dispensings during this period had a decreased risk of non-pathological fracture (odds ratio 0.48 [95% CI 0.27-0.83]) after adjustment for age, number of hospital admissions during the previous year, chronic disease score, and use of non-statin lipid-lowering drugs. No association was found between fracture risk and fewer than 13 dispensings of statins or between fracture risk and use of non-statin lipid-lowering drugs. INTERPRETATION Statins seem to be protective against non-pathological fracture among older women. These findings are compatible with the hypothesis that statins increase bone mineral density in human beings and thereby decrease the risk of osteoporotic fractures.

Active surveillance of vaccine safety : A system to detect early signs of adverse events

Background: There currently are no population-based systems in the United States to rapidly detect adverse events after newly introduced vaccines. To evaluate the feasibility of developing such systems, we used 5 years of data from 4 health maintenance organizations within the Centers for Disease Control and Prevention (CDC) Vaccine Safety Datalink. Methods: Within every year, each weeks vaccinated children were followed for 4 weeks, and rates of adverse events were compared with rates among children of similar ages before the introduction of the new vaccine. We assessed risks for intussusception after rotavirus vaccination and risks for fever, seizures, and other neurologic adverse events after the change from whole cell diphtheria-tetanus-pertussis (DTPw) to acellular DTP vaccine (DTPa). We used sequential probability ratio testing, adjusted for age, sex, calendar time, season, and HMO, and with a stopping value based on the probability of an adverse event under the null hypothesis and under a preset alternative hypothesis. Results: We detected an increase in intussusception after 2589 vaccine doses of rotavirus vaccine, about the same time initial reports of intussusception were made to the Vaccine Adverse Events Reporting System. Decreases in risk for fever, seizures, and other abnormal neurologic events became detectable within 12 weeks, 42 weeks, and 18 months, respectively, after the change from DTPw to DTPa. Conclusions: We conclude that it is feasible to develop systems for rapid and routine population-based assessments of new vaccine safety.

Using risk-adjustment models to identify high-cost risks.

Background. We examine the ability of various publicly available risk models to identify high-cost individuals and enrollee groups using multi-HMO administrative data. Methods. Five risk-adjustment models (the Global Risk-Adjustment Model [GRAM], Diagnostic Cost Groups [DCGs], Adjusted Clinical Groups [ACGs], RxRisk, and Prior-expense) were estimated on a multi-HMO administrative data set of 1.5 million individual-level observations for 1995–1996. Models produced distributions of individual-level annual expense forecasts for comparison to actual values. Prespecified “high-cost” thresholds were set within each distribution. The area under the receiver operating characteristic curve (AUC) for “high-cost” prevalences of 1% and 0.5% was calculated, as was the proportion of “high-cost” dollars correctly identified. Results are based on a separate 106,000-observation validation dataset. Main Results. For “high-cost” prevalence targets of 1% and 0.5%, ACGs, DCGs, GRAM, and Prior-expense are very comparable in overall discrimination (AUCs, 0.83–0.86). Given a 0.5% prevalence target and a 0.5% prediction threshold, DCGs, GRAM, and Prior-expense captured

Chronic disease score as a predictor of hospitalization

963,000 (approximately 3%) more “high-cost” sample dollars than other models. DCGs captured the most “high-cost” dollars among enrollees with asthma, diabetes, and depression; predictive performance among demographic groups (Medicaid members, members over 64, and children under 13) varied across models. Conclusions. Risk models can efficiently identify enrollees who are likely to generate future high costs and who could benefit from case management. The dollar value of improved prediction performance of the most accurate risk models should be meaningful to decision-makers and encourage their broader use for identifying high costs.

Effect of increased cost-sharing on oral hypoglycemic use in five managed care organizations : How much is too much?

Background. The Chronic Disease Score is a risk-adjustment metric based on age, gender, and history of dispensed drugs. We compared four versions of the score for their ability to predict hospitalization among members of eight health maintenance organizations nationwide. Methods. The study included 29,247 women age 45 years and older. Logistic regression models were constructed using rank quintile and rank decile indicators for each of four scores as predictors of hospitalization during the year after 1 October 1995. Discrimination and model fit were compared using several model properties including the C statistic and the odds ratio comparing highest with lowest quantiles. Results. All Chronic Disease Score versions performed similarly, with the version that predicts total healthcare cost, proposed by Clark et al. (Med Care 1995;33:783–795), performing somewhat better than the other three. The overall risk of hospitalization was 12%. Individuals with higher quantile ranks had a higher risk of hospitalization. Among the Chronic Disease Score versions, the risk of hospitalization ranged from 4% for the lowest decile to 27–29% for the highest decile. Odds ratios comparing the highest with the lowest deciles ranged from 8.9 to 10.2. Conclusions. The Chronic Disease Score predicts hospitalization and therefore may be a useful indicator of baseline comorbidity for control of confounding.

The health and economic benefits of influenza vaccination for healthy and at-risk persons aged 65 to 74 years.

Background:For patients with a chronic disease, increased cost-sharing for medications may lead to unintended consequences, including reduced use of medications essential for control of their disease. Objective:The objective of this study was to estimate the effects of small (

Cost effectiveness of influenza vaccination for healthy persons between ages 65 and 74 years

1–6 per 30-day supply), moderate (

Validation of diagnoses of peptic ulcers and bleeding from administrative databases: a multi-health maintenance organization study

7–10), and large (>

Vaccine Adverse Event Reporting System Reporting Source: A Possible Source of Bias in Longitudinal Studies

10) increases in medication cost-sharing on 12-month trends in oral hypoglycemic (OH) use among adults with type 2 diabetes. Methods:We conducted a quasiexperimental study using a time series with comparison group design. Data were obtained from computerized membership, benefit, and pharmacy dispensing data of 5 managed care organizations (MCOs). A total of 13,110 12-month episodes of OH use and a medication cost-sharing increase (“intervention”) were matched with 13,110 that had no increase. The dependent variable was OH average daily dose (ADD) standardized to each episodes mean OH ADD in the 6-month preintervention period. The principal independent variable was change in cost per 30-day OH supply between the 6-month pre- and postintervention periods. Effects of changes in cost-sharing on OH ADD were estimated using segmented time series regression. Results:Episodes with >

Simulated anthrax attacks and syndromic surveillance

10 increase in cost-sharing had significantly (α = 0.05) decreased OH ADD in the postintervention period. At 6 months after this increase, OH ADD had decreased by 18.5% from that predicted from the preintervention trend. Episodes with a