Test-Retest Reliability of the Reintegration to Normal Living Index (RNL-I) to Assess Perceived Participation in Adults With Late Effects of Polio.

BACKGROUND: Many individuals with late effects of polio have difficulties participating in daily activities. The Reintegration to Normal Living Index (RNL-I) is a self-report questionnaire that evaluates perceived participation, but knowledge of the test-retest reliability and measurement errors in this population is lacking.

OBJECTIVE: To evaluate the test-retest reliability of the RNL-I in adults with late effects of polio.

DESIGN: A postal survey with a test-retest design.

SETTING: University hospital outpatient clinic.

PARTICIPANTS: Fifty-one adults (20 women and 31 men; mean age 72 years) with late effects of polio.

MAIN OUTCOME MEASUREMENTS: The Reintegration to Normal Living Index (RNL-I).

METHODS: The participants responded to the RNL-I twice, 3 weeks apart. Data were analyzed with the following statistical methods: percentage agreement (PA), quadratic kappa coefficients, the intraclass correlation coefficient (ICC), mean difference, standard error of measurement (SEM/SEM%), and the smallest real difference (SRD/SRD%).

RESULTS: The PA (ie, the same scoring at both test occasions) was >70% for 10 of 11 items. The kappa coefficients showed good test-retest agreement (>0.61) for 7 items. The ICC was 0.88 and the mean difference was -0.74. The SEM (SEM%) was 7.4 (9.7%) and the SRD (SRD%) was 20.5 (27.0%).

CONCLUSION: The RNL-I can be considered reliable for adults with mild to moderate late effects of polio. It can thereby be used to assess changes in perceived participation over time or after rehabilitation interventions, both for a group of individuals and a single individual.

LEVEL OF EVIDENCE: III.