Development and Psychometric Validation of a Knowledge, Attitudes, and Practices Questionnaire on Pulmonary Embolism and Its Modifiable Risk Factors (PE-KAP-RO): Protocol for a Cross-Sectional Study in Adults from Western Romania

Background/Objectives: Venous thromboembolism (VTE), whose most severe manifestation is pulmonary embolism (PE), is the third most common acute cardiovascular disorder, and many of its risk factors≠—obesity, physical inactivity, smoking, and unfavorable dietary patterns—are modifiable. No validated instrument is currently available to assess knowledge, attitudes, and practices (KAP) regarding PE among adults in Romania, and the burden of self-reported thromboembolic risk factors in community settings has not been described with standardized measures. This protocol describes the development and psychometric validation of the PE-KAP-RO questionnaire, an integrated assessment tool comprising three scored KAP scales, three embedded validated lifestyle instruments, and an exploratory, unweighted VTE risk-factor burden index. No participants had been enrolled and no data had been collected at the time of submission; all procedures are therefore described as planned. Methods: The study comprises two phases. Phase 1 (development) includes qualitative concept elicitation with members of the target population, guideline- and theory-anchored item generation, expert content validation quantified by the content validity index, and pilot testing with cognitive debriefing (n ≈ 30). Phase 2 is a cross-sectional field validation in at least 450 adults (≥18 years) from Western Romania—with recruitment continuing toward 600 where feasible—through combined in-person (quota-guided) and online sampling that includes healthcare professionals, with test–retest re-administration in a subsample of at least 60 participants after 14 ± 4 days. Physical activity, diet, and nicotine dependence will be measured with the IPAQ-SF, MEDAS, and FTND. Sample size is justified separately for each analysis (precision of proportions, correlation and regression power, events per variable, split-sample factor analysis, item response theory calibration, and reliability estimation). Measurement properties will be evaluated against pre-specified acceptance criteria: item difficulty 0.20–0.80 (a screening range interpreted together with discrimination) and corrected item–total correlations ≥ 0.30; internal consistency (KR-20/Cronbach’s alpha and McDonald’s omega) 0.70–0.95; test–retest ICC ≥ 0.70 and item-level weighted kappa ≥ 0.60; structural validity by split-sample exploratory and confirmatory factor analysis (CFI/TLI ≥ 0.90, RMSEA ≤ 0.08, SRMR ≤ 0.08); item response theory calibration with formal model comparison and differential item functioning screening; construct validity requiring confirmation of ≥75% of a priori hypotheses; floor/ceiling effects < 15%; and measurement invariance across sex, age group, and administration mode. Expected Results: The study will deliver a validated Romanian-language instrument, a structured characterization of PE-related knowledge, attitudes, and preventive practices, and the distribution of self-reported risk factors in the study sample. Conclusions: PE-KAP-RO is intended as a standardized assessment tool for PE-related knowledge, attitudes, and practices; the risk-factor burden index is descriptive and does not estimate VTE probability; any future predictive tool would require a separate cohort followed for incident VTE. Reporting follows the STROBE recommendations and COSMIN-based methodology; the protocol is presented prior to participant enrollment.