Methodology and reporting characteristics of studies using interrupted time series design in healthcare

BMC Medical Research Methodology

Craig R. Ramsay¹  Jemma Hudson¹  Shona Fielding² 

[1] Health Services Research Unit, University of Aberdeen, Health Sciences Building;Medical Statistics Team, Institute of Applied Health Sciences, University of Aberdeen;

关键词: Interrupted time series;    Quasi-experimental;    Healthcare interventions;   

DOI  :  10.1186/s12874-019-0777-x

来源: DOAJ

【 摘 要 】

Abstract Background Randomised controlled trials (RCTs) are considered the gold standard when evaluating the causal effects of healthcare interventions. When RCTs cannot be used (e.g. ethically difficult), the interrupted time series (ITS) design is a possible alternative. ITS is one of the strongest quasi-experimental designs. The aim of this methodological study was to describe how ITS designs were being used, the design characteristics, and reporting in the healthcare setting. Methods We searched MEDLINE for reports of ITS designs published in 2015 which had a minimum of two data points collected pre-intervention and one post-intervention. There was no restriction on participants, language of study, or type of outcome. Data were summarised using appropriate summary statistics. Results One hundred and sixteen studies were included in the study. Interventions evaluated were mainly programs 41 (35%) and policies 32 (28%). Data were usually collected at monthly intervals, 74 (64%). Of the 115 studies that reported an analysis, the most common method was segmented regression (78%), 55% considered autocorrelation, and only seven reported a sample size calculation. Estimation of intervention effects were reported as change in slope (84%) and change in level (70%) and 21% reported long-term change in levels. Conclusions This methodological study identified problems in the reporting of design features and results of ITS studies, and highlights the need for future work in the development of formal reporting guidelines and methodological work.

【 授权许可】

Unknown