Table 1.

Summary of the search strategy

Search concepts*	Interrupted time series analysis (eg, interrupted time series analysis OR ITS studies OR interrupted time series OR time series OR trend analysis OR segmented regression OR Piecewise regression OR broken-stick regression) AND healthcare QI interventions (eg, quality improvement OR healthcare quality OR quality control OR quality assurance OR clinical audit).
Databases	MEDLINE, EMBASE, CINAHL, Web of Science, Global Health, Google Scholar, Africa-Wide, Latin American and Caribbean Health Sciences Literature (LILACS), Index Medicus for the South-east Asian Region (IMSEAR), Index Medicus for the Eastern Mediterranean Region (IMEMR), and Western Pacific Rim Region Index Medicus (WPRIM).
Other search strategies	Complementing electronic databases, hand searches of the bibliographies of relevant published works and previous reviews, relevant conference proceedings (eg, International Forum on Quality and Safety in Healthcare, Institute of Healthcare Improvement) were also performed.
Restrictions	No restrictions applied on date of publication, language of study, participants, or the type of QI outcome.

*Search terms were combined using appropriate Boolean operators and included subject heading terms and/or key words for two key themes (interrupted time series analysis and healthcare quality improvement) and were adjusted to fit each database requirements.

ITS, interrupted time series; QI, quality improvement.