Effect of home-based rehabilitation in frail older adults after cardiac surgery: a prospective feasibility study.

There is no control group. Everyone received the programme, so the improvement by six weeks may reflect natural recovery after surgery, usual outpatient care or community physiotherapy rather than Vivifrail. Numbers are small: 38 people started and 29 were assessed at six weeks, and the authors state the study was not powered to draw a definitive conclusion. The 55% cut-off used to split people into adherent and non-adherent groups was chosen after the data were collected and the authors call it arbitrary, although they report that other cut-offs (60%, 65%, 70%) did not change the results. People who dropped out tended to have recovered more quickly and had better function at the start, so those who remained for follow-up may have been those with more room to improve; the authors describe this as a possible selection bias. Participants carried on with usual care and could consult a community physiotherapist alongside the programme, and the extra physiotherapy was not adjusted for in the analysis.

The authors declare no conflicts of interest. The study was conducted within a fixed budget as part of routine care, and no external funder is named.

Do not read the improvement in SPPB scores as proof the Vivifrail programme works. There was no control group, and participants who completed the most sessions improved no more than those who completed the fewest (p = 0.37), so ordinary recovery after surgery could explain the gains.