Data sources
Two independent reviewers performed an electronic search using the following keywords: ”total quality management”, “quality improvement”, ”guidelines adherence”, ”appropriateness criteria”, ”appropriate use”, ”exercise test”, “stress test”, “cardiac imaging”, “echocardiogram”, and “echocardiography”. The references of the included studies, other systematic reviews, and meta-analyses were also manually reviewed to obtain a comprehensive list of studies. After identifying relevant studies, the full texts of the selected articles were examined by both reviewers based on inclusion criteria. Disagreements were resolved by consensus.