Validation of the patients' perceived involvement in care scale among patients with chronic pain.

Aim: The aim of this study was to evaluate the psychometric properties of the Icelandic version of the Modified Patients' Perceived Involvement in Care Scale (M-PICS), I-PICS, an instrument measuring patients' perceptions of pain-related communication with health care providers (HCP).

Methods: The M-PICS was translated into Icelandic according to standard procedures for forward and backward translation. The questionnaire consisted of 20 items measuring four constructs: (i) the degree to which the HCP was perceived as controlling the information-exchange process; (ii) to what extent patients sought or shared information with their HCP; (iii) patients' perceived encouragement to raise questions and discuss their symptoms with their health care provider and (iv) patients' perceived participation in decision-making during the health care visit. The response options for each item ranged from one to five on a 5-point Likert scale, where higher scores indicated higher endorsement.

Results: One hundred and forty-nine participants with pain lasting longer than three months (77.2% women; mean age, 49.9 years) completed the questionnaire. To examine the construct validity of the I-PICS, a confirmatory factor analysis was performed, specifying four factors in congruence with the theoretical underpinnings of the original modified scale (M-PICS). Of the 20 items, 19 were retained, and the I-PICS factor structure was for the most part identical to the M-PICS, with the exception of three items that moved between factors and one item that did not fall decisively on one specific factor. Internal consistency (alpha) for the four factors ranged from 0.74 to 0.86 and was 0.86 for the total scale. The mean score on the total I-PICS was 2.67 on a one to five scale, ranging from 1.21 to 4.28 (possible range, 1-5).

Conclusion: This study supports the four-factor structure of the M-PICS and that the I-PICS is a valid and reliable instrument for assessing patient-HCP communication.