What works for which riders, and to what extent? Evaluating the effectiveness of a New Zealand therapeutic riding intervention using a single-case experimental design

Abstract

Therapeutic horse riding (THR) is a complex intervention using horses and horse-related activities to positively influence health in people who experience disability. It is difficult to meaningfully evaluate the effectiveness of complex rehabilitation interventions with parallel randomised controlled trial methods when used in isolation. Reducing intervention complexities to simple variables for the purposes of minimising bias can enhance claims regarding causal associations between variables, but can result in difficulties translating the findings from these studies to ‘real world’ clinical practice where complexity is a certainty. This study aimed to evaluate the effectiveness of a therapeutic horse riding (THR) intervention using a single-case experimental design (SCED). A randomised, multiple-baseline SCED replicated across 12 participants, was used to quantitatively evaluate in which riders, and to what extent, changes in balance, functional performance, social responsiveness, quality of life and participation outcomes occurred as a result of the 20-week THR intervention. Analysis of data included analysis of individual participant responses (i.e., visual analysis, descriptive nonparametric approaches, analyses considering baseline stability evaluated with Mean Phase Difference and Slope and Level Change procedures) and between participant responses (i.e., Modified Brinley plots, estimation of effect sizes). An inconsistent intervention response to THR was seen across participants in the SCED. Participation outcomes measured using the Canadian Occupation Performance Measure (COPM) demonstrated the most consistent positive between-phase difference (performance score ES = 1.23; satisfaction score ES = 1.11). However, when taking baseline data stability into account these improvements only reached clinical significance for two of the participants. Being involved in THR may improve participation outcomes for some children who live with the experience of disability. SCED's provide a rigorous but clinically meaningful way to evaluate the effectiveness of complex rehabilitation interventions in real world.