Abstract
BACKGROUND
No consensus exists on the optimal treatment for irritable bowel syndrome (IBS). Psychological treatments are increasingly advocated but their effectiveness is unclear.
OBJECTIVES
To evaluate the efficacy of psychological interventions for the treatment of irritable bowel syndrome.
SEARCH STRATEGY
A computer assisted search of MEDLINE, EMBASE, PsychInfo, CINAHL, Web of Science, The Cochrane Library and Google Scholar was performed for the years 1966-2008. Local databases were searched in Europe.
SELECTION CRITERIA
Randomised trials comparing single psychological interventions with either usual care or mock interventions in patients over 16 years of age. No language criterion was applied.
DATA COLLECTION AND ANALYSIS
The search identified 25 studies that fulfilled the inclusion criteria. The relative risk (RR), risk difference (RD), number needed to treat (NNT) and standardized mean difference (SMD) along with 95% confidence intervals were calculated using a random effects model for each outcome.
MAIN RESULTS
Psychological interventions as a group The SMD for symptom score improvement at 2 and 3 months was 0.97 (95% CI 0.29 to 1.65) and 0.62 (95% CI 0.45 to 0.79) respectively compared to usual care. Against placebo, the SMDs were 0.71 (95% CI 0.08 to 1.33) and -0.17 (95% CI -0.45 to 0.11) respectively. For improvement of abdominal pain, the SMDs at 2 and 3 months were 0.54 (95%CI 0.10 to 0.98) and 0.26 (95% CI 0.07 to 0.45) compared to usual care. The SMD from placebo at 3 months was 0.31 (95% CI -0.16 to 0.79). For improvement in quality of life, the SMD from usual care at 2 and 3 months was 0.47 (95%CI 0.11 to 0.84) and 0.31 (95%CI -0.16 to 0.77) respectively. Cognitive behavioural therapy The SMD for symptom score improvement at 2 and 3 months was 0.75 (95% CI -0.20 to 1.70) and 0.58 (95% CI 0.36 to 0.79) respectively compared to usual care. Against placebo, the SMDs were 0.68 (95% CI -0.01 to 1.36) and -0.17 (95% CI -0.45 to 0.11) respectively. For improvement of abdominal pain, the SMDs at 2 and 3 months were 0.45 (95% CI 0.00 to 0.91) and 0.22 (95% CI -0.04 to -0.49) compared to usual care. Against placebo the SMD at 3 months was 0.33 (95% CI -0.16 to 0.82). For improvement in quality of life, the SMDs at 2 and 3 months compared to usual care were 0.44 (95% CI 0.04 to 0.85) and 0.92 (95% CI 0.07 to 1.77) respectively.Interpersonal psychotherapy The RR for adequate relief of symptoms was 2.02 (95% CI 1.13 to 3.62), RD 0.30 (95% CI 0.13 to 0.46), NNT 4 for comparison with care as usual. The SMD for improvement of symptom score was 0.35 (95% CI -0.75 to 0.05) compared with usual care. Relaxation/Stress management The SMD in symptom score improvement at 2 months was 0.50 (95%CI 0.02 to 0.98) compared with usual care. The SMD in improvement of abdominal pain at 3 months was 0.02 (95%CI -0.56 to 0.61) compared with usual care. Long term results Very few long term follow-up results were available. There was no convincing evidence that treatment effects were sustained following completion of treatment for any treatment modality.
AUTHORS' CONCLUSIONS
Psychological interventions may be slightly superior to usual care or waiting list control conditions at the end of treatment although the clinical significance of this is debatable. Except for a single study, these therapies are not superior to placebo and the sustainability of their effect is questionable. The meta-analysis was significantly limited by issues of validity, heterogeneity, small sample size and outcome definition. Future research should adhere to current recommendations for IBS treatment trials and should focus on the long-term effects of treatment.
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