Serious reporting deficiencies exist in minimal important difference studies: current state and suggestions for improvement.

BACKGROUND AND OBJECTIVES: To evaluate reporting of minimal important difference (MID) estimates using anchor-based methods for patient-reported outcome measures (PROMs), and the association with reporting deficiencies on their credibility. METHODS: Systematic survey of primary studies empirically estimating MIDs. We searched Medline, EMBASE, PsycINFO, and the Patient-Reported Outcome and Quality of Life Instruments Database until October 2018. We evaluated study reporting, focusing on participants' demographics, intervention(s), characteristics of PROMs and anchors, and MID estimation method(s). We assessed the impact of reporting issues on credibility of MID estimates. RESULTS: In 585 studies reporting on 5,324 MID estimates for 526 distinct PROMs, authors frequently failed to adequately report key characteristics of PROMs and MIDs, including minimum and maximum values of PROM scale, measure of variability accompanying the MID estimate and number of participants included in the MID calculation. Across MID estimates (n = 5,324), the most serious reporting issues impacting credibility included infrequent reporting of the correlation between the anchor and PROM (66%), inadequate details to judge precision of MID point estimate (13%), and insufficient information about the threshold used to ascertain MIDs (16%). CONCLUSION: Serious issues of incomplete reporting in the MID literature threaten the optimal use of MID estimates to inform the magnitude of effects of interventions on PROMs.

Minimal important difference estimates for patient-reported outcomes: A systematic survey.

OBJECTIVES: The objective of the study was to develop an inventory summarizing all anchor-based minimal important difference (MID) estimates for patient-reported outcome measures (PROMs) available in the medical literature. STUDY DESIGN AND SETTING: We searched MEDLINE, EMBASE, CINAHL, PsycINFO, and the Patient-Reported Outcome and Quality of Life Instruments Database internal library (January 1989-October 2018). We included primary studies empirically calculating an anchor-based MID estimate for any PROM in adults and adolescents. Pairs of reviewers independently screened and selected studies, extracted data, and evaluated the credibility of the MIDs. RESULTS: We identified 585 eligible studies, the majority conducted in Europe (n = 211) and North America (n = 179), reporting 5,324 MID estimates for 526 distinct PROMs. Investigators conducted their studies in the context of patients receiving surgical (n = 105, 18%), pharmacological (n = 85, 15%), rehabilitation (n = 65, 11%), or a combination of interventions (n = 194, 33%). Of all MID estimates, 59% (n = 3,131) used a global rating of change anchor. Major credibility limitations included weak correlation (n = 1,246, 23%) or no information regarding the correlation (n = 3,498, 66%) between the PROM and anchor and imprecision in the MID estimate (n = 2,513, 47%). CONCLUSION: A large number of MIDs for assisting in the interpretation of PROMs exist. The MID inventory will facilitate the use of MID estimates to inform the interpretation of the magnitude of treatment effects in clinical research and guideline development.

Evaluating the credibility of anchor based estimates of minimal important differences for patient reported outcomes: instrument development and reliability study.

OBJECTIVE: To develop an instrument to evaluate the credibility of anchor based minimal important differences (MIDs) for outcome measures reported by patients, and to assess the reliability of the instrument. DESIGN: Instrument development and reliability study. DATA SOURCES: Initial criteria were developed for evaluating the credibility of anchor based MIDs based on a literature review (Medline, Embase, CINAHL, and PsycInfo databases) and the experience of the authors in the methodology for estimation of MIDs. Iterative discussions by the team and pilot testing with experts and potential users facilitated the development of the final instrument. PARTICIPANTS: With the newly developed instrument, pairs of masters, doctoral, or postdoctoral students with a background in health research methodology independently evaluated the credibility of a sample of MID estimates. MAIN OUTCOME MEASURES: Core credibility criteria applicable to all anchor types, additional criteria for transition rating anchors, and inter-rater reliability coefficients were determined. RESULTS: The credibility instrument has five core criteria: the anchor is rated by the patient; the anchor is interpretable and relevant to the patient; the MID estimate is precise; the correlation between the anchor and the outcome measure reported by the patient is satisfactory; and the authors select a threshold on the anchor that reflects a small but important difference. The additional criteria for transition rating anchors are: the time elapsed between baseline and follow-up measurement for estimation of the MID is optimal; and the correlations of the transition rating with the baseline, follow-up, and change score in the patient reported outcome measures are satisfactory. Inter-rater reliability coefficients (ĸ) for the core criteria and for one item from the additional criteria ranged from 0.70 to 0.94. Reporting issues prevented the evaluation of the reliability of the three other additional criteria for the transition rating anchors. CONCLUSIONS: Researchers, clinicians, and healthcare policy decision makers can consider using this instrument to evaluate the design, conduct, and analysis of studies estimating anchor based minimal important differences.

Drug treatments for covid-19: living systematic review and network meta-analysis

OBJECTIVE: To compare the effects of treatments for coronavirus disease 2019 (covid-19). DESIGN: Living systematic review and network meta-analysis. DATA SOURCES: WHO covid-19 database, a comprehensive multilingual source of global covid-19 literature, up to 3 December 2021 and six additional Chinese databases up to 20 February 2021. Studies identified as of 1 December 2021 were included in the analysis. STUDY SELECTION: Randomised clinical trials in which people with suspected, probable, or confirmed covid-19 were randomised to drug treatment or to standard care or placebo. Pairs of reviewers independently screened potentially eligible articles. METHODS: After duplicate data abstraction, a bayesian network meta-analysis was conducted. Risk of bias of the included studies was assessed using a modification of the Cochrane risk of bias 2.0 tool, and the certainty of the evidence using the grading of recommendations assessment, development, and evaluation (GRADE) approach. For each outcome, interventions were classified in groups from the most to the least beneficial or harmful following GRADE guidance. RESULTS: 463 trials enrolling 166 581 patients were included; 267 (57.7%) trials and 89 814 (53.9%) patients are new from the previous iteration; 265 (57.2%) trials evaluating treatments with at least 100 patients or 20 events met the threshold for inclusion in the analyses. Compared with standard care, three drugs reduced mortality in patients with mostly severe disease with at least moderate certainty: systemic corticosteroids (risk difference 23 fewer per 1000 patients, 95% credible interval 40 fewer to 7 fewer, moderate certainty), interleukin-6 receptor antagonists when given with corticosteroids (23 fewer per 1000, 36 fewer to 7 fewer, moderate certainty), and Janus kinase inhibitors (44 fewer per 1000, 64 fewer to 20 fewer, high certainty). Compared with standard care, two drugs probably reduce hospital admission in patients with non-severe disease: nirmatrelvir/ritonavir (36 fewer per 1000, 41 fewer to 26 fewer, moderate certainty) and molnupiravir (19 fewer per 1000, 29 fewer to 5 fewer, moderate certainty). Remdesivir may reduce hospital admission (29 fewer per 1000, 40 fewer to 6 fewer, low certainty). Only molnupiravir had at least moderate quality evidence of a reduction in time to symptom resolution (3.3 days fewer, 4.8 fewer to 1.6 fewer, moderate certainty); several others showed a possible benefit. Several drugs may increase the risk of adverse effects leading to drug discontinuation; hydroxychloroquine probably increases the risk of mechanical ventilation (moderate certainty). CONCLUSION: Corticosteroids, interleukin-6 receptor antagonists, and Janus kinase inhibitors probably reduce mortality and confer other important benefits in patients with severe covid-19. Molnupiravir and nirmatrelvir/ritonavir probably reduce admission to hospital in patients with non-severe covid-19. SYSTEMATIC REVIEW REGISTRATION: This review was not registered. The protocol is publicly available in the supplementary material. READERS' NOTE: This article is a living systematic review that will be updated to reflect emerging evidence. Updates may occur for up to two years from the date of original publication. This is the fifth version of the original article published on 30 July 2020 (BMJ 2020;370:m2980), and previous versions can be found as data supplements. When citing this paper please consider adding the version number and date of access for clarity.