Quality of reporting of confounding remained suboptimal after the STROBE guideline

Koen B Pouwels; Niken N Widyakusuma; Rolf H H Groenwold; Eelko Hak

doi:10.1016/j.jclinepi.2015.08.009

Quality of reporting of confounding remained suboptimal after the STROBE guideline

J Clin Epidemiol. 2016 Jan:69:217-24. doi: 10.1016/j.jclinepi.2015.08.009. Epub 2015 Aug 29.

Authors

Koen B Pouwels¹, Niken N Widyakusuma², Rolf H H Groenwold³, Eelko Hak⁴

Affiliations

¹ Unit of PharmacoEpidemiology and PharmacoEconomics, Department of Pharmacy, University of Groningen, Antonius Deusinglaan 1, XB45, Groningen 9713 AV, The Netherlands. Electronic address: k.b.pouwels@gmail.com.
² Unit of PharmacoEpidemiology and PharmacoEconomics, Department of Pharmacy, University of Groningen, Antonius Deusinglaan 1, XB45, Groningen 9713 AV, The Netherlands.
³ Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Universiteitsweg 100, Utrecht 3584 CX, The Netherlands.
⁴ Unit of PharmacoEpidemiology and PharmacoEconomics, Department of Pharmacy, University of Groningen, Antonius Deusinglaan 1, XB45, Groningen 9713 AV, The Netherlands; Department of Epidemiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, Postbus 30 001, Groningen 9700 RB, The Netherlands.

PMID: 26327488
DOI: 10.1016/j.jclinepi.2015.08.009

Abstract

Objectives: Poor quality of reporting of confounding has been observed in observational studies prior the STrenghtening the Reporting of Observational studies in Epidemiology (STROBE) statement, a reporting guideline for observational studies. We assessed whether the reporting of confounding improved after the STROBE statement.

Study design and setting: We searched MEDLINE for all articles about observational cohort and case-control studies on interventions with a hypothesized beneficial effect in five general medical and five epidemiologic journals published between January 2010 and December 2012. We abstracted data for the baseline period before the publication of the STROBE statement (January 2004-April 2007) from a prior study. Six relevant items related to confounding were scored for each article. A comparison of the median number of items reported in both periods was made.

Results: In total, 174 articles published before and 220 articles published after the STROBE statement were included. The median number reported items was similar before and after the publication of the STROBE statement [median, 4; interquartile range [IQR], 3-5 vs. median, 4; IQR, 3.75-5]. However, the distribution of the number of reported items shifted somewhat to the right (P = 0.01).

Conclusion: Although the quality of reporting of confounding improved in certain aspects, the overall quality remains suboptimal.

Keywords: Confounding factors; Editorial policies; Epidemiology; Guideline adherence; Guidelines as topics; Publishing/standards.

Publication types

Research Support, Non-U.S. Gov't
Review

MeSH terms

Case-Control Studies
Confounding Factors, Epidemiologic*
Humans
Observational Studies as Topic
Practice Guidelines as Topic*
Research Design / standards*