Abstract
Background
Psychological stress has been widely implicated in asthma exacerbation. Evidence suggests that written emotional disclosure, an intervention that involves writing about traumatic or stressful experiences, helps to reduce stress and promote physical and psychological well-being. Written emotional disclosure may have a role in the management of asthma.
Objectives
This review aims to determine the effectiveness of written emotional disclosure for people with asthma, specifically, to assess:
1. overall efficacy of emotional disclosure compared with emotionally neutral writing on self reported quality of life in people with asthma;
2. overall efficacy of emotional disclosure compared with emotionally neutral writing on objective measures of health outcome in people with asthma; and
3. comparative efficacy of different types of emotional disclosure for people with asthma.
Search methods
Trials were identified from the Cochrane Airways Group Specialised Register of trials, CENTRAL, MEDLINE, EMBASE, CINAHL, AMED and PsycINFO. The latest search was conducted in January 2014.
Selection criteria
Randomised controlled trials published in any language comparing written emotional disclosure intervention versus a control writing (emotionally neutral) intervention in participants with asthma were included in the review.
Data collection and analysis
Two review authors independently assessed studies against predetermined inclusion criteria and extracted the data. Corresponding authors were contacted when necessary to provide additional information.
Main results
Four studies, involving a total of 414 participants, met the inclusion criteria. Three studies were conducted in adult participants and one in adolescents. The average age of participants ranged from 14 to 43 years. The trials lasted between two months and 12 months. The interventions were based on Pennebaker's method. The risk of bias across most domains of the studies was generally considered to be low, however three of four studies were considered at high risk of bias due to lack of assessor blinding and one study was at high risk of bias for selective reporting. The interpretation of these studies was limited by diverse outcome measurements, measurement tools, control group techniques, and number and/or times of follow-up. A pooled result from the four studies, including a total of 146 intervention and 135 control participants, indicated uncertain effect in forced expiratory volume in one second (FEV1) % predicted between the disclosure group and the control group (mean difference (MD) 3.43%, 95% confidence interval (CI) -0.61% to 7.47%; very low-quality evidence) at <= three months' follow-up. Similarly, evidence from two studies indicated that written emotional disclosure found uncertain effect on forced vital capacity (FVC) (standardised mean difference (SMD) -0.02, 95% CI -0.30 to 0.26; low-quality evidence) and asthma symptoms (SMD -0.22, 95% CI -0.52 to 0.09; low-quality evidence) but may result in improved asthma control at <= three months' follow-up (SMD 0.29, 95% CI 0.01 to 0.58; low-quality evidence). We were unable to pool the data for other outcomes. Results from individual trials did not reveal a significant benefit of written emotional disclosure for quality of life, medication use, healthcare utilisation or psychological well-being. Evidence from one trial suggests a significant reduction in beta agonist use (MD -1.62, 95% CI -2.62 to -0.62; low-quality evidence) at <= three months' follow-up in the disclosure group compared with controls. The review did not address any adverse effects of emotional writing.
Authors' conclusions
Evidence was insufficient to show whether written emotional disclosure compared with writing about non-emotional topics had an effect on the outcomes included in this review. Evidence is insufficient to allow any conclusions as to the role of disclosure in quality of life, psychological well-being, medication use and healthcare utilisation. The evidence presented in this review is generally of low quality. Better designed studies with standardised reporting of outcome measurement instruments are required to determine the effectiveness of written emotional disclosure in the management of asthma.