Psychometric evaluation of a Patient Satisfaction Survey Questionnaire to assess advanced practice nurse ambulatory services in primary care

Aim To determine the construct validity and test-retest reliability of the Patient Satisfaction Survey Questionnaire (PSSQ). Background Advanced practice nurses (APNs) co-manage patients with non-communicable diseases (NCDs) with public primary care physicians in Singapore. The original Nurse Practitioner Satisfaction Survey (NPSS) instrument was adapted (renamed as PSSQ) to assess satisfaction with APN service. Method A total of 209 patients self-administered the PSSQ at first visit and repeated it in a retest through phone within the next 2 weeks in 2018. Cronbach's alpha and intra-class correlation (ICC) coefficients were performed to evaluate the internal consistency and test-retest reliability. Construct validity was determined by confirmatory factor analysis (CFA). Results The overall Cronbach's alpha (>0.7) and ICC scores (0.697-0.729) indicated excellent test-retest reliability and good internal consistency, respectively. The CFA results of three-factor model showed poor fit. Additional exploratory factor analysis (EFA) and principal component analysis (PCA) with varimax rotation revealed that adding another factor (communication with physician) resulted in a better model (eigenvalue > 1). The ICC for the four-factor model ranged from 0.664 to 0.825, indicating fair to excellent reliability. Conclusion The PSSQ shows good internal consistency and test-retest reliability. The four-factor model is a better instrument to assess APN service in local populations. Implications for Nursing Management The validated PSSQ can be used as instrument to assess the quality of services provided by various categories of nurses, including registered nurses, nurse clinicians and APNs.