Quality of the clinical evidence Five studies were identified for inclusion within the review. For the critical outcome of mortality the evidence was rated as very low quality due to risk of bias and imprecision as a result of wide confidence intervals surrounding the point estimate. For quality of life, which was also a critical outcome, the quality of the evidence ranged from high to very low depending on the scale used for measurement. The SF- 36 physical component summary and mental component summary were rated as low and very low quality respectively. This was again due to risk of bias, imprecision and heterogeneity in the results reported by the studies. For the EQ-5D utility score the evidence was rated as high quality; for the MLWHFQ the evidence was rated as moderate quality, due to imprecision. Several measures of exercise capacity were reported by the studies; these included the incremental shuttle walk test (ISWT), the 6 minute walk test (6MWT), VO2 max and the 10 metre walk test (fast). The quality of these outcomes ranged from very low to high quality, with outcomes being downgraded for risk of bias and imprecision. All of the included studies reported adherence to the intervention, which ranged in quality from moderate to very low. The outcome data reported by each study was not meta-analysed due to the significant degree of variation in the methods of obtaining this information across studies. The committee also noted that the subjective nature of the adherence data, when self-reported by people in a home- based exercise programme, meant that it was potentially less reliable. 