PMID- 33637039 OWN - NLM STAT- MEDLINE DCOM- 20210624 LR - 20220531 IS - 1471-2288 (Electronic) IS - 1471-2288 (Linking) VI - 21 IP - 1 DP - 2021 Feb 26 TI - Using a distribution-based approach and systematic review methods to derive minimum clinically important differences. PG - 41 LID - 10.1186/s12874-021-01228-7 [doi] LID - 41 AB - BACKGROUND: Clinical interpretation of changes measured on a scale is dependent on knowing the minimum clinically important difference (MCID) for that scale: the threshold above which clinicians, patients, and researchers perceive an outcome difference. Until now, approaches to determining MCIDs were based upon individual studies or surveys of experts. However, the comparison of meta-analytic treatment effects to a MCID derived from a distribution of standard deviations (SDs) associated with all trial-specific outcomes in a meta-analysis could improve our clinical understanding of meta-analytic treatment effects. METHODS: We approximated MCIDs using a distribution-based approach that pooled SDs associated with baseline mean or mean change values for two scales (i.e. Mini-Mental State Exam [MMSE] and Alzheimer Disease Assessment Scale - Cognitive Subscale [ADAS-Cog]), as reported in parallel randomized trials (RCTs) that were included in a systematic review of cognitive enhancing medications for dementia (i.e. cholinesterase inhibitors and memantine). We excluded RCTs that did not report baseline or mean change SD values. We derived MCIDs at 0.4 and 0.5 SDs of the pooled SD and compared our derived MCIDs to previously published MCIDs for the MMSE and ADAS-Cog. RESULTS: We showed that MCIDs derived from a distribution-based approach approximated published MCIDs for the MMSE and ADAS-Cog. For the MMSE (51 RCTs, 12,449 patients), we derived a MCID of 1.6 at 0.4 SDs and 2 at 0.5 SDs using baseline SDs and we derived a MCID of 1.4 at 0.4 SDs and 1.8 at 0.5 SDs using mean change SDs. For the ADAS-Cog (37 RCTs, 10,006 patients), we derived a MCID of 4 at 0.4 SDs and 5 at 0.5 SDs using baseline SDs and we derived a MCID of 2.6 at 0.4 SDs and 3.2 at 0.5 SDs using mean change SDs. CONCLUSION: A distribution-based approach using data included in a systematic review approximated known MCIDs. Our approach performed better when we derived MCIDs from baseline as opposed to mean change SDs. This approach could facilitate clinical interpretation of outcome measures reported in RCTs and systematic reviews of interventions. Future research should focus on the generalizability of this method to other clinical scenarios. FAU - Watt, Jennifer A AU - Watt JA AD - Knowledge Translation Program, Li Ka Shing Knowledge Institute, St. Michael's Hospital- Unity Health Toronto, 209 Victoria Street, East Building, Room 723, Toronto, Ontario, M5B 1W8, Canada. jennifer.watt@utoronto.ca. AD - Division of Geriatric Medicine, Department of Medicine, University of Toronto, 190 Elizabeth Street, R. Fraser Elliott Building, 3-805, Toronto, Ontario, M5G 2C4, Canada. jennifer.watt@utoronto.ca. FAU - Veroniki, Areti Angeliki AU - Veroniki AA AD - Knowledge Translation Program, Li Ka Shing Knowledge Institute, St. Michael's Hospital- Unity Health Toronto, 209 Victoria Street, East Building, Room 723, Toronto, Ontario, M5B 1W8, Canada. AD - Department of Primary Education, School of Education, University of Ioannina, 45110, Ioannina, Greece. AD - Department of Surgery & Cancer, Faculty of Medicine, Imperial College, Institute of Reproductive and Developmental Biology, W12 0NN, London, UK. FAU - Tricco, Andrea C AU - Tricco AC AD - Knowledge Translation Program, Li Ka Shing Knowledge Institute, St. Michael's Hospital- Unity Health Toronto, 209 Victoria Street, East Building, Room 723, Toronto, Ontario, M5B 1W8, Canada. FAU - Straus, Sharon E AU - Straus SE AD - Knowledge Translation Program, Li Ka Shing Knowledge Institute, St. Michael's Hospital- Unity Health Toronto, 209 Victoria Street, East Building, Room 723, Toronto, Ontario, M5B 1W8, Canada. AD - Division of Geriatric Medicine, Department of Medicine, University of Toronto, 190 Elizabeth Street, R. Fraser Elliott Building, 3-805, Toronto, Ontario, M5G 2C4, Canada. AD - Institute for Health Policy, Management and Evaluation, University of Toronto, 4th floor, 155 College St, Toronto, Ontario, M5T 3M6, Canada. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20210226 PL - England TA - BMC Med Res Methodol JT - BMC medical research methodology JID - 100968545 SB - IM MH - *Alzheimer Disease/diagnosis/drug therapy MH - Humans MH - *Minimal Clinically Important Difference MH - Outcome Assessment, Health Care MH - Research Design MH - Surveys and Questionnaires MH - Systematic Reviews as Topic PMC - PMC7912575 OTO - NOTNLM OT - Alzheimer disease assessment scale - cognitive subscale OT - Back-transformation OT - Meta-analysis OT - Mini-mental state exam OT - Minimum clinically important difference OT - Systematic review COIS- Authors have no competing interests to declare. EDAT- 2021/02/28 06:00 MHDA- 2021/06/25 06:00 PMCR- 2021/02/26 CRDT- 2021/02/27 05:26 PHST- 2020/11/23 00:00 [received] PHST- 2021/02/02 00:00 [accepted] PHST- 2021/02/27 05:26 [entrez] PHST- 2021/02/28 06:00 [pubmed] PHST- 2021/06/25 06:00 [medline] PHST- 2021/02/26 00:00 [pmc-release] AID - 10.1186/s12874-021-01228-7 [pii] AID - 1228 [pii] AID - 10.1186/s12874-021-01228-7 [doi] PST - epublish SO - BMC Med Res Methodol. 2021 Feb 26;21(1):41. doi: 10.1186/s12874-021-01228-7.