Inclusion and exclusion criteria

Studies on the development of assessment of measurement properties of cardiac self-efficacy instruments for individuals with CAD will be included without language and date restrictions. Translation of other languages will be performed by language experts. Clinical trials or validation studies using self-reported or proxy-reported measurements and those published as abstracts will be excluded. Moreover, studies of instruments that have self-efficacy in their construct (eg, self-management, self-care) will also be excluded, limiting to self-efficacy instruments for coronary patients.

Search strategy

The search strategy will be conducted from database inception to the date of the final searches in MEDLINE (ovid), Web of Science, EMBASE and PsycINFO databases considering the following: (1) construct of interest (cardiac self-efficacy); (2) target population (individuals with CAD); (3) type of instrument (questionnaire or scale) and (4) measurement properties; the latter will be assessed using search filters validated for measurement studies and already applied in previous reviews. Additional searches for relevant studies will be manually performed in reference lists of primary studies and review articles. Searches will be repeated before the final analysis to check for new studies. Online supplemental file 1 shows the search strategies we developed for the databases search. The study will follow COSMIN recommendations.²⁰

Screening and selection of studies

The search results will be imported into the reference list management tool Mendeley (https://www.mendeley.com). Duplicates will be deleted before selections, and the reference list exported to the Rayyan Qatar Computing Research Institute systematic review platform (https://rayyan.qcri.org).²¹ The detailed selection process will be presented in the PRISMA-P flowchart.

Two independent authors (JABA and DAL) will select studies using titles and abstracts, conduct a complete reading of potentially eligible studies and identify and record reasons for excluding those ineligible. In the case of disagreement, a virtual meeting will be held for discussion and consultation with a third reviewer (LPG).

Data extraction

Two authors (JABA and DAL) will extract data following the Cochrane Collaboration and PRISMA guidelines. Other authors will independently review data to verify inclusion and exclusion criteria. The extracted information will include first author, year of publication, general characteristics of the instrument (construct, subscales, number of items and version), study design, sample size, characteristics of individuals (eg, age, sex, location, country, language, methods for selecting participants and response rate) and results of measurement properties (ie, internal consistency, reliability, measurement error, content validity (including face validity), construct validity (subdivided into structural validity, hypothesis testing and cross-cultural validity), validity of criterion, responsiveness and interpretability (not a measurement property, but necessary to adapt a research instrument or clinical practice)).

Data quality

Methodological quality of studies will be assessed by two independent authors (RBF and JCL) using COSMIN RoB Checklist.^{18 19} This tool considers 10 measurement properties and contains nine boxes with 3 to 35 items. Each box assigns a methodological quality score for instrument development: (1) content validity, (2) structural validity, (3) internal consistency, (4) cross-cultural validity and measurement invariance, (5) reliability, (6) measurement error, (7) criterion validity, (8) hypothesis testing for construct validity and (9) responsiveness. Each item has four response options: inadequate, doubtful, adequate and very good.²² Disagreements will be solved by a third author (KSM).

The content extracted from measurement instruments will be compared using the ICF framework.^23–25 Two independent authors (JABA and RBF) will evaluate the content and link items of questionnaires to ICF standards. After, a third author (JCL) will review the content.

Data synthesis

A narrative synthesis of results will be provided. In the possibility of validation studies of the same instrument for different populations, methodological and psychometric properties, quality of such studies will be addressed as a unique instrument but discussing the particularity of each version. A combination of measurement properties will determine the overall evidence of the instrument. Studies will be grouped according to similarity in terms of language, instrument version, study population and application form.

Results will be evaluated in clusters or summarised against the criteria for good measurement properties to determine whether they are sufficient (+), insufficient (−), inconsistent (±) or indeterminate (?). Furthermore, a modified Grading of Recommendations, Assessment, Development and Evaluation will determine study quality.^{26 27}

Afterward, instruments will be categorised and justified according to COSMIN recommendations:²⁸ (A) instrument is recommended for use and results are reliable; (B) when it may be recommended but requires further research to assess quality of these instruments and (C) instrument should not be recommended.

Patient and public involvement

None.