Adherence to post-operative pain medication after discharge following day case orthopaedic surgery at a South African private hospital

Abstract

Background: Adherence to post-operative pain medication remains a concern as low adherence rates result in suboptimal clinical outcomes, and burdens the global healthcare environment. The primary treatment goals of medications prescribed after surgery are to achieve sufficient pain control with minimal side effects to ensure optimisation of post-operative recovery. A limited number of studies have been conducted on adherence to post-operative pain medication, in orthopaedic day case surgery in South Africa. This study could contribute to the knowledge of factors affecting adherence to pain medication after surgery. Objective: The purpose of this study was to investigate whether patients were adherent to postoperative discharge analgesics after orthopaedic day case surgery in a South African private hospital. Furthermore, demographical variables, smoking, pain, side effects and normal adherence behaviour were studied as possible factors that may affect adherence. Method: The study followed an observational, prospective, cross-sectional design using a structured questionnaire as data-collection tool, conducted through a telephonic interview on the fourth day after surgery. The inclusion criteria of the study included 120 participants, 18 years of age and older, undergoing day case orthopaedic surgery. Participants were excluded if they could not be reached on the fourth day after surgery, after two attempts to contact them. The data collection was conducted between June 2016 and June 2017. The participants conducted a pill count, which was used to determine overall adherence. Self-reported adherence behaviour and normal adherence behaviour was established from the questionnaire. The association between participant demographics, smoking status, type and intensity of side effects, pain severity involving sleep and mobility, and adherence was determined from the structured questionnaire. Results: A total of 120 participants were included in the study. Among them, 69 were females and 51 males. The overall adherence rate determined from the pill count was 56.7% (n = 68). No association was found between gender (p = 0.140), age (p = 0.822), smoking status (p = 1.000) and adherence to post-operative discharge pain medication. Although more than 80% of participants experienced moderate to severe pain during movement; it had no impact on participants’ adherence to prescribed analgesia (pain when repositioning in bed p = 0.237; pain when walking, standing, sitting p = 0.509). The disruption of sleep by moderate to severe pain affected adherence to post-operative discharge pain medication negatively (pain interfering with falling asleep p = 0.001; pain causing awakening from sleep p = 0.035). Adherence status was independent of the type and number of side effects experienced from the multimodal analgesic regimens (nausea 30.0%, p = 0.809; drowsiness 55.9%, p = 0.701; gastritis 12.5%, p = 0.403; constipation 59.2%, p = 0.300; dizziness 26.7%, p = 0.956). Self-reporting of adherence to the current prescribed post-operative discharge medication was shown to be dependent on overall adherence found from the pill count (p < 0.001, Cramér’s V = 0.5). Conclusions and recommendations: The study attempted to reveal actual adherence as well as possible factors affecting adherence to prescribed post-operative discharge medication. Adherence was poor at 56.7% and interventions to increase the adherence should be considered. Pain interrupting sleep showed a dependent relationship to non-adherence. Participant education on timing of doses should be considered to optimise the drug level in the body over the sleeping period. As moderate to severe pain was experienced during movement post discharge, it could be suggested that surgeons increase intra-operative pain management techniques, e.g. intra-articular injections of analgesics.