Adherence to weight loss medications; post-marketing study from HMO pharmacy data of one million individuals

Diabetes Res Clin Pract. 2011 Nov;94(2):269-75. doi: 10.1016/j.diabres.2011.08.021. Epub 2011 Sep 9.

Abstract

Introduction: Post-marketing data on weight-loss medications in free living population are a necessary adjunct to data from clinical trials.

Materials and methods: We conducted a population-based analysis of first-time medication users based on HMO pharmacy purchasing data serving > one million adults.

Results: During 5 years, usage of orlistat and sibutramine more than doubled and rates were higher during the months May-Aug. As compared to non-users (n = 1,038,828), annual weight-loss drug users (n = 7175) had higher women proportion, body-mass-index (BMI), bariatric surgery history, and usage of diabetes, depression, and cardiovascular medications (p < 0.001 for all). Among users, men had higher BMI (34.4 kg/m(2) vs. 32.5 kg/m(2)), prevalence of diabetes (25.4% vs. 10.7%) and heart disease (14.2% vs. 3.5%) than women. Mean duration of purchasing weight-loss medications was 2.1 months for orlistat and 2.9 months for sibutramine. Fewer than 2% completed 12 months of weight-loss medication therapy. Among the 25% who continued to purchase at least 4 months, BMI (sub-group analysis) reduced from 33.02 kg/m(2) to 32.04 kg/m(2) (p < 0.001). In a multivariate model, long-term adherence (≥ 4 months) to weight-loss medications was associated with use of sibutramine vs. orlistat (OR = 2.08; 95%CI: 1.76-2.45), and prevalence of diabetes (OR = 1.20; 95%CI: 1.01-1.25). Age, gender, and baseline BMI were not associated with long-term adherence.

Conclusions: Usage of weight-loss drugs is higher among diabetes patients. However, the poor adherence to therapy is substantially below levels reported in clinical trials.

MeSH terms

  • Adult
  • Analysis of Variance
  • Anti-Obesity Agents / therapeutic use*
  • Body Mass Index
  • Comorbidity
  • Cyclobutanes / therapeutic use*
  • Diabetes Mellitus / epidemiology
  • Female
  • Health Care Surveys
  • Health Maintenance Organizations / statistics & numerical data*
  • Humans
  • Insurance, Pharmaceutical Services / statistics & numerical data*
  • Israel / epidemiology
  • Lactones / therapeutic use*
  • Logistic Models
  • Male
  • Medication Adherence / statistics & numerical data*
  • Middle Aged
  • Obesity / diagnosis
  • Obesity / drug therapy*
  • Obesity / epidemiology
  • Odds Ratio
  • Orlistat
  • Product Surveillance, Postmarketing
  • Registries
  • Time Factors
  • Treatment Outcome
  • Weight Loss / drug effects*
  • Young Adult

Substances

  • Anti-Obesity Agents
  • Cyclobutanes
  • Lactones
  • Orlistat
  • sibutramine