Design and selection of items for a new health-related quality of life instrument with infertility patients (Infertility-QoL): a national multicenter, four-phase, mixed-methods study.

BACKGROUND

Infertility is a global issue that significantly imposes physical and psychosocial burdens on both female and male patients, affecting their health-related quality of life (HRQoL) and family wellbeing. The aim of this study was to develop a de novo HRQoL instrument for male and female infertility patients in China, and describe the generation and selection of items for Infertility-QoL.

METHODS

This study used a mixed methods design involving 4 steps. The items identified from the systematic review and qualitative interview analysis were used to construct draft candidate items (step 1). In order to ensure item relevance, comprehension, and acceptability, using cognitive interviews prior to quantifying psychometric testing (step 2). In the third step, we conducted a cross-sectional quantitative offline survey for item selection. Classical test theory (CTT) and item response theory (IRT) were used to assess dimensionality and performance of items. Finally, by conducting advisory committee consultations and thematic seminars, the items were further qualitatively evaluated, and developed a formal version of the Infertility-QoL (step 4).

RESULTS

Step 1 resulted in the generation of 73 items. Based on CTT and IRT psychometric evidence, 36 items were deleted. Finally, according to the advisory committee consultations for qualitative evaluation, a formal version of the Infertility-QoL with 25 items was developed. The exploratory factor analysis results showed that the 6-factor model was appropriate. The newly developed instrument (Infertility-QoL) consisted of 25 items across six dimensions: physical health, sexual life, emotional status, self-efficacy, subjective wellbeing and social relations.

CONCLUSIONS

This study developed the new Infertility-QoL instrument for male and female infertility patients, and preliminarily verified its dimensions.