Predictors of Adherence to a Step Count Intervention Following Total Knee Replacement: An Exploratory Cohort Study

• Published in: The journal of orthopaedic and sports physical therapy 2022-09, Vol.52 (9), p.620-629
• Main Authors: Duong, Vicky, Dennis, Simone, Ferreira, Manuela L., Heller, Gillian, Nicolson, Philippa J.A., Robbins, Sarah R., Wang, Xia, Hunter, David J.
• Format: Article
• Language: English
• ISSN: 0190-6011; 1938-1344
• DOI: 10.2519/jospt.2022.11133

OBJECTIVETo explore the person-level predictors of adherence to a step count intervention following total knee replacement (TKR). DESIGNProspective cohort study, nested within the PATHway trial. METHODSParticipants who had recently undergone TKR were recruited from 3 rehabilitation hospitals in Sydney, Australia, for the main trial. Only data from participants who were randomized to the TKR intervention group were analyzed. Participants in the intervention group (n = 51) received a wearable tracker to monitor the number of steps taken per day. Step count adherence was objectively measured at 3 months as the number of steps completed divided by the number prescribed and multiplied by 100 to express adherence as a percentage. Participants were classified into 4 groups: withdrawal, low adherence (0%-79%), adherent (80%-100%), and >100% adherent. Ordinal logistic regression was used to identify which factors predicted adherence to the prescribed step count. RESULTSOf the 51 participants enrolled, nine (18% of 51) withdrew from the study before 3 months. Half of participants were classified as >100% adherent (n = 24%, 47%). Ten were classified as low adherence (20%), and 8 participants were classified as adherent (16%). In the univariable model, lower age (OR 0.90; 95% CI 0.83-0.97), higher patient activation (OR 1.03; 95% CI 1.00-1.06), and higher technology self-efficacy (OR 1.03; 95% CI 1.00-1.06) were associated with higher adherence. After adjusting for age in the multivariable model, patient activation and technology self-efficacy were not significant. CONCLUSIONYounger age, higher patient activation, and higher technology self-efficacy were associated with higher adherence to a step count intervention following TKR in the univariable model. Patient activation and technology self-efficacy were not associated with higher adherence following adjustment for age. J Orthop Sports Phys Ther 2022;52(9):620-629. Epub: 9 July 2022. doi:10.2519/jospt.2022.11133.