Reliability and validity of the Maltese version of the perception of anticoagulant treatment questionnaire (PACT-Q)

Purpose: Anticoagulant therapy has an impact on the health-related quality of life, as it is a chronic treatment for most clinical indications and also requires some lifestyle changes. Since there was no validated questionnaire available in the Maltese language, the aim of our study was to translate and validate the Perception of Anticoagulant Treatment Questionnaire (PACT-Q2).

Patients and methods: The PACT-Q2 explores two dimensions (convenience and anticoagulant treatment satisfaction). Forward and backward translations were performed. The Maltese version of the PACT-Q2 was administered to 174 patients on warfarin treatment enrolled from different anticoagulation clinics in Malta. Reliability was assessed through internal consistency (Cronbach’s alpha) and test-retest (intraclass correlation coefficient [ICC]). Validity was assessed through floor/ceiling effect, factor analysis (root mean square error of approximation [RMSEA], standardized root mean squared residual [SRMR], goodness-of-fit index [GFI], adjusted goodness-of-fit index [AGFI], comparative fit index [CFI]), subscales correlation and known-group validity.

Results: Reliability was very good for the convenience subscale (Cronbach’s alpha 0.86, ICC 0.87), but less good for the satisfaction subscale (Cronbach’s alpha 0.62, ICC 0.40). Floor effect was 0%; ceiling effect was low (6.3% convenience, 1.2% satisfaction). Fit parameters were close to acceptable cut-offs (RMSEA =0.09, SRMR =0.10, GFI =0.82, AGFI =0.78, CFI =0.79). There was no correlation between the two subscales (r=0.01, p=0.83). Patients with history of bleeding showed lower convenience (r=−0.16, p=0.08) and lower satisfaction (r=−0.21, p=0.01).

Conclusions: Our results support the finding that the Maltese translation of the PACT-Q2 is a valid and reliable instrument.