The Impact on Life questionnaire: validation for elective surgery prioritisation in New Zealand prioritisation criteria in orthopaedic surgery.

AIM

This cohort study tested the reliability and validity of the Impact on Life (IoL) patient-rated questionnaire for use in prioritising orthopaedic procedures.

METHODS

Three hundred and twenty-four patients completed the questionnaire during specialist orthopaedic assessments over a 5-month period in 2013. The reliability and validity of the IoL were tested against the SF-12 and Oxford scores. Correlation analysis was used to assess patient- and surgeon-rated scores. Internal consistency reliability was assessed using Cronbach's alpha. Patient- and surgeon-rated scores were further analysed between patients added to the waiting list and those that were not.

RESULTS

Participants' mean age was 58 years (range 18-88). Reliability analysis showed the IoL had excellent internal consistency with a Cronbach's alpha of 0.926, reaching the threshold for clinical application. Construct validity of the IoL was confirmed with significant correlation with other validated quality of life measures (p<0.01). T-tests indicated that patients placed on the waiting list had significantly higher surgeon and IoL scores (p<0.001), compared with those not placed on the waiting list.

CONCLUSION

Our results support the IoL as a valid and reliable method of assessing patient-rated quality of life and recommend its use in the Orthopaedic Clinical Priority Assessment Criteria score.