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.