Christopher Baethge1,2, Markus Deckert3, Andreas Stang3,4. 1. Department of Psychiatry and Psychotherapy, University of Cologne Medical School, Cologne, Germany. 2. Deutsches Ärzteblatt and Deutsches Ärzteblatt International, Editorial Offices, Cologne, Germany. 3. Center of Clinical Epidemiology, c/o Institute of Medical Informatics, Biometry and Epidemiology, University Hospital of Essen, Essen, Germany. 4. Department of Epidemiology, Boston University School of Public Health, Boston, Massachusetts.
Abstract
OBJECTIVE: To analyze the reporting of statistical inference in psychiatry. METHOD: We searched 63,928 abstracts, published in 15 leading psychiatric journals (1975-2015). RESULTS: Median abstract length increased from 664 (1975) to 1,323 (2015) characters, and median use of numbers from two to 14/abstract. A total of 3.6% of all abstracts exclusively contained significance terminology in a nonstatistical sense, and 45% showed some form of statistical inference, increasing from 26% to 52%. In those abstracts, statistical inference based on thresholds was dominant. Its proportion decreased from 99% to 66%, but with rising numbers of articles, figures rose from 1,095 to 2,382. Although reporting p values without thresholds did not appear 40 years ago and remains rare, combining precise p values with thresholds is now common. In 2010-2015, 86% of abstracts contained p values or p value thresholds, 22% confidence intervals, and 7% confidence intervals only. Results varied across journals. CONCLUSION: There is a moderate shift from reporting p values along set thresholds, such as p ≤ 0.05, to presenting precise p values and confidence intervals, but not as pronounced as in epidemiology and general medicine. The long debate on estimation over testing has not led to a substantial replacement of p values by confidence intervals. Null hypothesis testing ("p ≤ .05") dominates statistical thinking.
OBJECTIVE: To analyze the reporting of statistical inference in psychiatry. METHOD: We searched 63,928 abstracts, published in 15 leading psychiatric journals (1975-2015). RESULTS: Median abstract length increased from 664 (1975) to 1,323 (2015) characters, and median use of numbers from two to 14/abstract. A total of 3.6% of all abstracts exclusively contained significance terminology in a nonstatistical sense, and 45% showed some form of statistical inference, increasing from 26% to 52%. In those abstracts, statistical inference based on thresholds was dominant. Its proportion decreased from 99% to 66%, but with rising numbers of articles, figures rose from 1,095 to 2,382. Although reporting p values without thresholds did not appear 40 years ago and remains rare, combining precise p values with thresholds is now common. In 2010-2015, 86% of abstracts contained p values or p value thresholds, 22% confidence intervals, and 7% confidence intervals only. Results varied across journals. CONCLUSION: There is a moderate shift from reporting p values along set thresholds, such as p ≤ 0.05, to presenting precise p values and confidence intervals, but not as pronounced as in epidemiology and general medicine. The long debate on estimation over testing has not led to a substantial replacement of p values by confidence intervals. Null hypothesis testing ("p ≤ .05") dominates statistical thinking.
Authors: David Moher; Sally Hopewell; Kenneth F Schulz; Victor Montori; Peter C Gøtzsche; P J Devereaux; Diana Elbourne; Matthias Egger; Douglas G Altman Journal: BMJ Date: 2010-03-23
Authors: Ross D Crosby; Stephen A Wonderlich; James E Mitchell; Martina de Zwaan; Scott G Engel; Kevin Connolly; Chris Flessner; Jennifer Redlin; Mary Markland; Heather Simonich; Traci L Wright; Jodi M Swanson; Mohammad Taheri Journal: Int J Eat Disord Date: 2006-01 Impact factor: 4.861