[Design and validation of an instrument about quality of the advance care planning for professionals]

To develop a questionnaire aimed to measure the quality of the advance care planning process in healthcare professionals and to assess its psychometric quality.

Instrumental questionnaire validation study.

primary care centers and outpatients clinics from general hospitals in Ferrol, Ourense, Monforte-Lugo and Health Area V of the Health Service of Asturias.

physicians and nurses. Phases: (1) design of the first version of the questionnaire using the Delphi technique; (2) construction of the second version of 21 items, after judges' agreement and Kendall's W test; (3) pilot study: internal consistency using Cronbach's alpha and omega coefficient, retest-test by Pearson's correlation coefficient; (4) validation: Barlett's spherity test and Kaiser-Meyer-Olkin measurement, exploratory factor analysis with varimax rotation and study of the dimensions of the questionnaire (number, CCI and correlation), internal consistency using Cronbach's alpha.

Pilot study with 28 professionals. Reliability ɷ=0.917, α=0.841, and test-retest correlation coefficient of 0.785 (95% confidence interval: 0.587-0.894; p<0.001). Validation of the questionnaire (21 items) in 204 professionals. Ítem analysis and exploratory factor analysis (Barlett's test [χ²=1298,789] and KMO=0.808; p<0.001) yielded a five-factor model explaining 64.377% of the total variance, with 18 items grouped into 5 dimensions (information, preferences, behavioral intention, training and communication). Cronbach's alpha of the global questionnaire was 0.841.

The ProPAD-pro questionnaire has showed to be a valid and reliable instrument to assess the quality of the advance care planning process.