Research
Print page Print page
Switch language
The Capital Region of Denmark - a part of Copenhagen University Hospital
Published

A systematic literature review on the efficacy-effectiveness gap: comparison of randomized controlled trials and observational studies of glucose-lowering drugs

Research output: Contribution to journalReviewResearchpeer-review

DOI

  1. Completeness of RET testing in patients with medullary thyroid carcinoma in Denmark 1997-2013: a nationwide study

    Research output: Contribution to journalJournal articleResearchpeer-review

  2. The Danish in-hospital cardiac arrest registry (DANARREST)

    Research output: Contribution to journalReviewResearchpeer-review

  3. The positive predictive value of spontaneous subarachnoid hemorrhage diagnoses in the Danish National Patient Register

    Research output: Contribution to journalJournal articleResearchpeer-review

  1. The "RCT augmentation": a novel simulation method to add patient heterogeneity into phase III trials

    Research output: Contribution to journalJournal articleResearchpeer-review

  2. Assessment of channeling bias among initiators of glucose-lowering drugs: A UK cohort study

    Research output: Contribution to journalJournal articleResearchpeer-review

  3. Lean body mass change over 6 years is associated with dietary leucine intake in an older Danish population

    Research output: Contribution to journalJournal articleResearchpeer-review

  4. The "Efficacy-Effectiveness Gap": Historical Background and Current Conceptualization

    Research output: Contribution to journalJournal articleResearchpeer-review

  5. Dietary protein and urinary nitrogen in relation to 6-year changes in fat mass and fat-free mass

    Research output: Contribution to journalJournal articleResearchpeer-review

View graph of relations

AIM: To identify a potential efficacy-effectiveness gap and possible explanations (drivers of effectiveness) for differences between results of randomized controlled trials (RCTs) and observational studies investigating glucose-lowering drugs.

METHODS: A systematic literature review was conducted in English language articles published between 1 January, 2000 and 31 January, 2015 describing either RCTs or observational studies comparing glucagon-like peptide-1 analogs (GLP-1) with insulin or comparing dipeptidyl peptidase-4 inhibitors (DPP-4i) with sulfonylurea, all with change in glycated hemoglobin (HbA1c) as outcome. Medline, Embase, Current Content, and Biosis were searched. Information on effect estimates, baseline characteristics of the study population, publication year, study duration, and number of patients, and for observational studies, characteristics related to confounding adjustment and selection- and information bias were extracted.

RESULTS: From 312 hits, 11 RCTs and 7 observational studies comparing GLP-1 with insulin, and from 474 hits, 16 RCTs and 4 observational studies comparing DPP-4i with sulfonylurea were finally included. No differences were observed in baseline characteristics of the study populations (age, sex, body mass index, time since diagnosis of type 2 diabetes mellitus, and HbA1c) or effect sizes across study designs. Mean effect sizes ranged from -0.43 to 0.91 and from -0.80 to 1.13 in RCTs and observational studies, respectively, comparing GLP-1 with insulin, and from -0.13 to 2.70 and -0.20 to 0.30 in RCTs and observational studies, respectively, comparing DPP-4i and sulfonylurea. Generally, the identified observational studies held potential flaws with regard to confounding adjustment and selection- and information bias.

CONCLUSIONS: Neither potential drivers of effectiveness nor an efficacy-effectiveness gap were identified. However, the limited number of studies and potential problems with confounding adjustment, selection- and information bias in the observational studies, may have hidden a true efficacy-effectiveness gap.

Original languageEnglish
JournalClinical Epidemiology
Volume9
Pages (from-to)41-51
Number of pages11
ISSN1179-1349
DOIs
Publication statusPublished - 2017
Externally publishedYes

    Research areas

  • Journal Article, Review

ID: 52388110