Observational and clinical trial findings on the comparative effectiveness of diabetes drugs showed agreement.

TitleObservational and clinical trial findings on the comparative effectiveness of diabetes drugs showed agreement.
Publication TypeJournal Article
Year of Publication2015
AuthorsFlory JH, Mushlin AI
JournalJ Clin Epidemiol
Date Published2015 Feb
KeywordsBody Weight, Diabetes Mellitus, Type 2, Female, Glycated Hemoglobin A, Humans, Hypoglycemic Agents, Metformin, Middle Aged, Multivariate Analysis, Observational Studies as Topic, Randomized Controlled Trials as Topic, Sulfonylurea Compounds, Treatment Outcome, Weight Gain

OBJECTIVES: This study compares an observational study of diabetes treatment effectiveness to randomized controlled trials to assess their convergent validity.

STUDY DESIGN AND SETTING: Multivariate models were developed using observational data to describe change in hemoglobin A1c (HbA1c; % unit) and weight (kilograms) after addition of a second-line oral diabetes drug to metformin monotherapy. Randomized trials of these scenarios were systematically identified. The models were used to simulate each trial, and simulated and actual results were compared by linear regression and meta-analysis.

RESULTS: Thirty-two randomized trials of second-line diabetes oral therapy were identified. For all outcomes and drugs studied, simulation and actual results correlated (P < 0.001). There were no statistically significant differences between meta-analyzed randomized and simulated results for effect on HbA1c. For effect on weight, results were qualitatively comparable, but for sulfonylureas, the simulated weight gain was nominally greater than seen in the randomized controlled trials.

CONCLUSION: An observational study of diabetes drug effectiveness showed convergent validity with randomized data. This supports cautious use of the observational research to draw conclusions about drug effectiveness in populations not studied in clinical trials. This approach may be useful in other situations where observational and randomized data need integration.

Alternate JournalJ Clin Epidemiol
PubMed ID25432086
PubMed Central IDPMC4349393
Grant ListL30 DK099830 / DK / NIDDK NIH HHS / United States
UL1 TR000457 / TR / NCATS NIH HHS / United States
UL1 TR002384 / TR / NCATS NIH HHS / United States
/ / Intramural NIH HHS / United States
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