Reliability of the revised scoliosis research society22 and oswestry disability index (ODI) questionnaires in adult spinal deformity when administered by telephone

Abstract Background Context Non-response rates are as high as 20-50% after 5 years of follow-up in adult spinal deformity (ASD) surgery. Minimizing loss to follow-up is essential to protect data quality in long-term studies. Phone and internet administration of outcomes instruments have grown in popularity and have been found to not only provide a convenient way of collecting data, but have also been shown to improve response rates. Purpose To examine reliability the revised Scoliosis Research Society-22 (SRS-22r) and Oswestry Disability Index questionnaires in adult spinal deformity (ASD) when administered by telephone. Study Design/Setting Single-center, randomized crossover phone validation of ASD patients Patient Sample ASD Patients presenting to tertiary spine care center Outcomes Measures ODI, SRS-22r Methods 49 patients (mean age 55.7 years) with ASD were randomized in a 1:1 ratio to either phone completion of the SRS-22r and ODI first followed by in-office completion, or to in-office completion followed by phone completion. An interval of 2-4 weeks was placed between administrations of each version. A paired t-test was used to assess for a difference in the written versus phone forms and intraclass correlation coefficients were used to assess homogeneity. Finally, goodness-of-fit testing was used to assess version preference. Results There was no significant difference between the phone and in-office versions of the SRS-22r (p-value = 0.174) or the ODI (p-value = 0.320). The intraclass correlation coefficients of the SRS-22r and ODI were 0.91and 0.86, respectively. Completion over the phone was the most popular option (57% preferred phone, 29% preferred in-office, and 14% had no preference). Conclusions Phone administration of the SRS-22r and ODI to ASD patients provides a convenient and reliable tool for reducing loss of follow-up data.