A Cochrane review [Abstract] 1 included 17 studies with a total of 1 006 subjects. There was a significant reduction in reports of chest pain in the first three months following the intervention (RR 0.70, 95% CI 0.53 to 0.92; statistical heterogeneity, I2 =59%). This was maintained from 3 to 9 months afterwards (RR 0.59, 95% CI 0.45 to 0.76). There was also a significant increase in the number of chest pain free days up to three months following the intervention (MD 3.00, 95% CI 0.23 to 5.77; statistical heterogeneity, I2 =68%). This was associated with reduced chest pain frequency (MD -2.26, 95% CI -4.41 to -0.12; statistical heterogeneity, I2 =94%) but there was no evidence of effect of treatment on chest pain frequency from 3 to 12 months (MD -0.81, 95% CI -2.35 to 0.74; statistical heterogeneity, I2 =75%). There was no effect on severity (MD -4.64, 95% CI -12.18 to 2.89; statistical heterogeneity, I2 =65%) up to 3 months after the intervention). Wide variability in outcome measures made integration of studies for secondary outcome measures difficult.
Comment: The quality of evidence is downgraded by study limitations (lack of blinding), and by inconsistency (unexplained variability in results).
Primary/Secondary Keywords