Psychometric assessment of the Chinese version of the Problems and Needs in Palliative Care questionnaire-short version in advanced cancer patients.

BACKGROUND

To determine the validity, reliability and acceptability of the Mandarin Chinese version of the Problems and Needs in Palliative Care questionnaire-short version (PNPC-sv) for measuring problems and palliative care needs among patients with advanced cancer.

METHODS

This was a validation study using a forward- and backward- translation procedure, a panel of experts and a cross-sectional study design. The Mandarin Chinese version of the PNPC-sv was translated by four independent translators. The translated Chinese version was further reviewed by an expert panel to identify its content validity. A pilot test was conducted in 10 advanced cancer patients to preliminarily assess the face validity, readability and clarity of the pre-final version of the PNPC-sv. 178 patients with advanced cancer, regardless of their gender and types of cancer diagnosis, were further recruited through a convenience sampling from three tertiary hospitals in China to assess the psychometric properties of the PNPC-sv Mandarin Chinese version. Content validity was measured using the content validity index (CVI). Construct validity was estimated via confirmatory factor analysis and the contrasted groups approach. Concurrent validity was identified by analysing the correlations between the EORTC Quality-of-Life Questionnaire-Core 30 (EORTC QLQ-C30) and the PNPC-sv. Reliability of the PNPC-sv was examined with the internal consistency reliability and item-to-total correlations. Several closed-ended and open-ended questions were designed to explore its acceptability.

RESULTS

174 patients completed the questionnaires. High content and face validity were determined after the two rounds of assessment with the expert panel and the patients. An excellent CVI of 1.0 was achieved and patients rated the PNPC-sv as a useful instrument for assessing their problems and needs (mean score = 7.99, 0-10 scale) and reported the items were not particularly sensitive and easy to understand. The majority of the fit indexes meet the critical criteria, with the Chi-square divided by degrees of freedom (x/df) being 1.58 and 2.05, and the root mean squared error of approximation (RMSEA) being 0.06 and 0.07 for the problem part and need-for-care part, respectively. In relation to the contrasted groups analysis, it clearly discriminated the differences on the sub-scores of Activities of Daily Life (ADL), spiritual and psychological problems and needs between male and female patients; ADL, physical, social and financial problems and needs between age groups; and autonomic problems and needs between patients with different cancer stages. Statistically significant correlations (p < 0.05) were detected between the PNPC-sv and the EORTC QLQ-C30 in the majority of the sub-scores (positive correlations) and total scores (negative correlations). The Cronbach's alpha of the total scale was 0.88 and 0.91 for the problem part and need-for-care part, respectively. The Cronbach's alpha of the subscales were generally above 0.70. Item-to-total correlations were generally acceptable, with the majority of the values being above 0.40. The PNPC-sv questionnaire was reported to be convenient and easy to understand, and the average time for completing was 11 min.

CONCLUSIONS

The Mandarin Chinese version of the PNPC-sv is a valid, reliable and user-friendly instrument for measuring problems and palliative care needs among patients with advanced cancer. Further research is needed to further examine its psychometric properties particular internal structure in a larger patient sample.