Development of a scale to measure directive guidance by pharmacists

Abstract

Objective: To develop and test a questionnaire that can be used to measure directive guidance behaviors by pharmacists. QUESTIONNAIRE DESIGN: The Purdue Pharmacist Directive Guidance (PPDG) scale was developed based on the directive guidance dimension of socially supportive behaviors, as described by Barrera and Ainlay. The final scale consists of 10 items.

Subjects: Individuals on the Walker Test Crew database who were 18 years of age or older and self-reported taking medications for asthma, hypertension, and/or diabetes in the past 3 months were eligible for inclusion. All data were collected through telephone interviews. A total of 464 contacts were made, resulting in 300 responses.

Data analysis: Principal components analysis was performed to determine the construct subscales of the PPDG. Internal consistency of the PPDG and its subscales was assessed using Cronbach's alpha and corrected item-total correlations. Pearson product-moment correlations of the PPDG with measures of family and friend support (FFS) and self-reported medication adherence were used to determine convergent validity. Spearman rank-order correlations of the PPDG with the total number of prescription medications as well as those for asthma, hypertension, and diabetes taken in the past 3 months were obtained. ANOVA and Student's t-tests were used to determine differences in PPDG across demographic characteristics.

Results: Principal components analysis yielded two subscales for the PPDG. These were named Instruction and Feedback and Goal Setting, based on their content. The PPDG scale had good internal consistency (Cronbach's alpha = 0.86), and correlated positively and significantly with FFS (r = 0.27), giving some evidence of convergent validity. The PPDG scale and its subscales also had logically intuitive positive and significant correlations with the total number of prescription drugs taken in the past 3 months.

Conclusions: The PPDG is short and easy to administer, and showed validity and reliability. The PPDG scale should be useful in developing a better understanding of the process by which pharmacists influence healthcare outcomes, assessing variations in pharmaceutical care, and as a tool in identifying means of overcoming barriers to higher levels of pharmaceutical care.