Psychological interventions for improving adherence to inhaled therapies in people with cystic fibrosis

Background Adherence to treatment, including inhaled therapies, is low in people with cystic fibrosis (CF). Although psychological interventions for improving adherence to inhaled therapies in people with CF have been developed, no previous published systematic review has evaluated the evidence for efficacy of these interventions. Objectives The primary objective of the review was to assess the efficacy of psychological interventions for improving adherence to inhaled therapies in people with cystic fibrosis (CF). The secondary objective was to establish the most effective components, or behaviour change techniques (BCTs), used in these interventions. Search methods We searched the Cochrane Cystic Fibrosis Trials Register, which is compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched databases (PubMed; PsycINFO; EBSCO; Scopus; OpenGrey), trials registries (World Health Organization International Clinical Trials Registry Platform; US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov), and the reference lists of relevant articles and reviews, with no restrictions on language, year or publication status. Date of search: 7 August 2022. Selection criteria We included randomised controlled trials (RCTs) comparing different types of psychological interventions for improving adherence to inhaled therapies in people with CF of any age, or comparing psychological interventions with usual care. We included quasi-RCTs if we could reasonably assume that the baseline characteristics were similar in both groups. Data collection and analysis Two review authors independently assessed trial eligibility and completed data extraction, risk of bias assessments, and BCT coding (using the BCT Taxonomy v1) for all included trials. We resolved any discrepancies by discussion, or by consultation with a third review author as necessary. We assessed the certainty of the evidence using GRADE. We are uncertain whether motivational interviewing (MI) was better or worse than education plus problem-solving (EPS) at helping people with CF to take their inhaled treatments. Background CF is a chronic, genetic condition, usually diagnosed at birth through newborn screening. People with CF experience recurrent chest infections due to the build-up of thick, sticky mucus (or sputum) in their lungs and digestive systems. Inhaled treatments are usually prescribed to either thin sputum (making it easier to clear or cough up), or to treat and control bacteria in the lungs (to reduce infections). People living with any long-term health condition often struggle to take the number of treatments they are prescribed, and this is no different in CF. What did we want to find out? Can psychological interventions help people with CF to take their inhaled treatments, and are there any harmful or unwanted effects of these interventions (e.g. anxiety or depression)? Which techniques (e.g. goal-setting, problem-solving) work best at helping people with CF to take their inhaled treatments? What did we do? We searched for studies comparing different types of psychological interventions, or comparing the interventions with usual care, for helping people with CF of any age to take their inhaled treatments. We compared and summarised the results of the trials and rated our confidence in the evidence, based on factors such as the trial methods. What did we find? We included 10 trials with 1642 people with CF (approximately 54.3% female). Four trials included children and adolescents; five trials included adults; and one trial included both. Nine trials compared a psychological intervention with usual care, and one study compared two psychological interventions (MI versus EPS). People (or in one trial, CF centres) were randomly selected for one group or the other. People were followed up for between six to eight weeks and 23 months. Psychological interventions were wide-ranging. They included an intervention that combined digital technology (website or app) with support from trained healthcare professionals. Interventions used a range of techniques, with problem-solving and providing instructions on how to take treatments being the most commonly used. Main results Psychological interventions are probably better than usual care at helping people with CF to take their inhaled treatments, and may cause little or no harm (e.g. anxiety or depression) when measured six to 12 months after treatment. Psychological interventions may also improve perceived treatment burden (as measured using a quality of life (QoL) questionnaire). There was no evidence of a difference between groups in terms of lung function (a measure of how well someone's lungs are working), the number of chest infections, or perceived chest symptoms (again measured using a QoL questionnaire). We are uncertain whether MI was better or worse than EPS at helping people with CF to take their inhaled treatments, improving lung function or QoL, or reducing chest infections in people with CF. The included trial did not look at whether MI or EPS caused harm (e.g. anxiety or depression). What are the limitations of the evidence? Our confidence in the evidence for psychological interventions being better or worse than usual care ranges from low to moderate. The biggest included trial of psychological interventions (which had results from between six and 12 months after treatment started) focused on adults with CF (aged 16 years and over), whereas the question we wanted to answer was broader (i.e. we cannot be sure if the results would be the same in children). Large trials with a longer follow-up period (e.g. 12 months) are needed in children with CF. It is possible that because people completing the outcome assessments knew which group they were in, this might affect the results for QoL, anxiety and depression. We are not confident in the evidence comparing MI with EPS. The only trial examining this included a small number of adults, so we cannot be sure if the results would be the same in children or in a larger group of people. We are unsure whether participants were put into the different treatment groups truly at random, so differences between the groups might be due to differences between people rather than the treatments. We are also unsure about people leaving the trial early and how this might affect the results. We also think that because the people completing the outcome assessments knew which group they were in, this might affect the QoL results. Current evidence on which techniques (e.g. goal-setting, problem-solving) work best at helping people with CF to take their inhaled treatments is limited. Future trials should provide more details on the techniques used in interventions. How up to date is this evidence? The evidence is up to date to 7 August 2022.