Development and preliminary validation of the MedRisk instrument to measure patient satisfaction with chiropractic
Paul F Beattie1, Roger Nelson, Donald R Murphy
1Program in Physical Therapy, Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA. pbeattie@mailbox.sc.edu).
Objective:
The purpose of this study is to provide preliminary information regarding the factor-structure, group- and individual-level reliability, and criterion-referenced validity of measures obtained from the MedRisk Instrument for Measuring Patient Satisfaction with Chiropractic Care.
Method:
Three hundred twenty-three subjects who had completed a course of chiropractic care responded to questionnaire in which they rated their degree of satisfaction from 1 to 5 (1 = very unsatisfied to 5 = very satisfied) for each of 20 items. Factor structure was assessed using item-correlation and exploratory factor analysis. Group-level reliability for single test administration was assessed by calculating Cronbach α, and individual-level reliability was determined using the standard error of measure. Criterion-referenced validity was investigated by comparing the item scores and mean scores of individual factors to global measures of satisfaction.
Results:
Individual item scores ranged from 3.98 for "Office location was convenient" to 4.77 for "My chiropractor treats me respectfully." The items that were most highly correlated with overall patient satisfaction were "My chiropractor thoroughly explained the treatment I received" (r = 0.77) and "My chiropractor answered all of my questions" (r = 0.71). Exploratory factor analysis suggested a 2-factor solution: a 5-item "internal" factor and a 6-item "external" factor. The mean scores from these factors were correlated with the 2 global measures ranging from r = 0.68 to r = 0.80. The standard error of measure was 0.20 for the internal factor and 0.17 for the external factor.
Conclusions:
Preliminary assessment suggests that a 13-item version of the MedRisk instrument provides psychometrically sound measures to assess patient satisfaction with chiropractic care; however, additional confirmatory validation should be performed.
