Development and psychometric testing of the self-regulatory questionnaire for lung cancer screening (SRQ-LCS).

Abstract

BACKGROUND: Research implicates psychological factors in low uptake of lung cancer screening. We developed and psychometrically tested a standardised measure of these psychological determinants in preparation for a prospective, longitudinal cohort study of screening uptake. METHODS: Leventhal's Common-Sense Model of Self-Regulation of Health and Illness provided the theoretical framework to generate the initial item pool. Items were refined during expert review and cognitive interviews which tested for face validity, redundancy, acceptability and comprehensibility. An online survey piloted the refined pool with 1500 current and former (quit ≤ 15 years) smokers aged 55-80. The response distributions, internal reliability and factor structure determined the final retained constructs. Regression analyses examined these constructs' associations with screening intention, smoking status and demographics. RESULTS: The final measure included seven factor-derived subscales (consequences, personal control, treatment control, illness coherence, emotional representation, behavioural response and appraisal, risk perception) with Cronbach's alphas ranging from 0.59 to 0.91 and four single-item questions (response efficacy for smoking cessation, treatment intention, perceived stigma and lung cancer survival). Most constructs were associated with smoking status and screening intention (p's < .05). CONCLUSIONS: The Self-Regulatory Questionnaire for Lung Cancer Screening (SRQ-LCS) is an acceptable, reliable and valid measure for investigating the psychological determinants of screening uptake.