Development and psychometric assessment of a health action process approach (HAPA) inventory for home nutritional behavior among postoperative gastric cancer patients

Objective

The aim of this study was to develop and validate a health action process approach (HAPA) inventory for measuring cognitive belief factors influencing home nutritional behavior among postoperative gastric cancer patients.

Methods

Item pool of the inventory was constructed based on the HAPA, literature review, and qualitative interview. Expert consultations were used for item improvement. Then postoperative gastric cancer patients (n = 404) were surveyed to conduct item analysis, reliability and validity test of the inventory. Reliability was evaluated through internal, split-half, and test–retest reliability. Validity was assessed through content and construct validity.

Results

Starting with 44 items in the item pool, the final inventory comprised 23 items. The exploratory factor analysis identified six dimensions—namely, risk perception, outcome expectancy, self-efficacy, intention, action planning, coping planning. And the cumulative variance contribution rate was 70.676%. Confirmatory factor analysis showed the model fits well (χ² = 370.794, df = 214, and χ²/df = 1.733, root mean square of approximation error = 0.054, comparative fit index = 0.943, Tucker–Lewis index = 0.933, and incremental fitting index = 0.944). The item and scale level content validity were 0.83–1.00, and 0.98, which was considered good. The reliability was acceptable (Cronbach's α = 0.922, split-half reliability = 0.781, test–retest reliability = 0.716).

Conclusions

The developed inventory was valid and reliable to assess HAPA-based cognitive belief factors of home nutritional behavior of postoperative gastric cancer patients. Future research is needed to examine the applicability of the inventory in patients across diverse cultural backgrounds and healthcare systems.