Overuse and underuse of cardiovascular diagnostic and therapeutic procedures for community-dwelling adults: a protocol for a systematic review.

Potentially inappropriate care can result from overuse or underuse of treatments, tests, or procedures. Overuse is defined as the use of health services with no clear benefit to the recipient or where harms outweigh benefits and/or costs of care. Underuse is defined as failure to deliver an effective and cost-effective healthcare intervention. Cardiovascular procedures such as coronary artery bypass grafting, carotid endarterectomy, coronary angiography, and coronary angioplasty (with/without stenting) are potentially both underused and overused. This systematic review aims to identify rates of potential overuse and underuse of these cardiovascular procedures and explore any associated patient or healthcare system factors. A systematic review and meta-analysis will be conducted in accordance with the PRISMA guidelines. A systematic search of MEDLINE (via Ovid), Embase, Cumulative Index to Nursing and Allied Health Literature and the Cochrane library will be conducted using a predefined search strategy.  Eligible studies for inclusion will examine rates of overuse and underuse of cardiovascular procedures, measured against national/international guidelines, for adults aged ≥18 years. Primary observational studies including cross-sectional and cohort studies will be included. Titles, abstracts, and full texts will be screened for inclusion by two reviewers. Data will be extracted using a standardised form. Risk of bias for all included studies will be assessed using a modified version of the Hoy risk of bias tool. Where adequate data exists, and if statistically appropriate, meta-analyses will be conducted. If statistical pooling of the data is not possible, the findings will be narratively summarised focusing on the review's objectives. : This systematic review will examine overuse and underuse of cardiovascular procedures for adults.  The results will help inform policy makers, researchers, patients, and clinicians in the appropriate use of these procedures, in line with international guidelines. This protocol has been submitted for registration on PROSPERO (CRD42021239041).