A randomised controlled trial of the effectiveness of an exercise training program in patients recovering from SARS, 2005 Lau et al

rvallee

Senior Member (Voting Rights)
(This was about SARS, not properly controlled either)


A randomised controlled trial of the effectiveness of an exercise training program in patients recovering from severe acute respiratory syndrome

https://www.sciencedirect.com/science/article/pii/S0004951405700027

The aim of this study was to evaluate the effectiveness of an exercise training program on cardiorespiratory and musculoskeletal performance and health-related quality of life of patients who were recovering from severe acute respiratory syndrome (SARS).

A 6-week supervised exercise training program was carried out in the physiotherapy department of a university teaching hospital. One hundred and thirty-three patients referred from a SARS Review Clinic solely for physiotherapy were included. Cardiorespiratory fitness (6-minute walk test, Chester Step Test for predicting VO2max), musculoskeletal performance (isometric deltoid and gluteal muscles strength, handgrip strength, 1-minute curl-up and push-up tests) and health-related quality of life (SF-36) were measured and evaluated. Patients were assigned randomly to either a control group (standardised educational session about exercise rehabilitation) or an exercise group.

After 6 weeks, significantly greater improvement was shown in the exercise group in the 6-minute walk test (77.4 m vs 20.7 m, p < 0.001), VO2max (3.6 ml/kg/min vs 1 ml/kg/min, p = 0.04), and musculoskeletal performance (handgrip strength, curl-up and push-up tests, p < 0.05). Effects on health-related quality of life were not statistically significant.

It was concluded that the exercise training program was effective in improving both the cardiorespiratory and musculoskeletal fitness in patients recovering from SARS. However, health-related quality of life was not affected by physical training.
This is from the first SARS outbreak but there is so little research on it might as well post it. As is typical, this evaluated the very thing that the patients trained on, ignoring all other concerns.

I found this cited by an otherwise unremarkable paper making recommendations for Long Covid. Cited positively, of course.
 
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Note that this study had little to do with ME. This is just a generalised programme for people who were previously infected with the virus who were referred for physiotherapy. The study had a variety of medical exclusions too.

This was not a study of 'post-SARS-fatigue syndrome' or anything else along those lines. The fact that it was included as a recommendation for LongCovid just shows how important it is to actually check references before citing them in your manuscript. ;)
 
I also note that the training programme was 6 weeks long, with evaluation at the end. That is not long enough to identify any sustainable benefit. Those people with a post-viral fatigue syndrome/ME/CFS may be swapping out some of their tasks of daily living for the prescribed exercise.

Importantly, "effects on health-related quality of life" were not statistically significant.

VO2max wasn't actually measured. Instead, cardiorespiratory fitness was assessed using two measures where both familiarity and motivation could very easily result in better performances. The exercise group got to practice; the control group did not.

Patients had had SARS-1 and had been referred for physiotherapy, presumably because they were having ongoing problems with tasks of daily living. People who were "poorly motivated, uncooperative" were excluded from the study. Also, people with above-normal performance on the 6-minute walk test and Chester Step test were excluded. Of course, the fact that there were significant numbers of people with above-normal performance in cardiorespiratory measures but who still were fronting up to the medical system requesting help to regain function suggests that deconditioning wasn't their problem. Of the total 258 SARS patients at the clinic, 54 refused or were assessed as having 'above normal performance'. This selection of patients who only had sub-normal performance of cardiorespiratory measures is a bias. Are they suggesting that physical training should not be used in patients with post-viral impacts and above-normal walk test and step test performance?

Finally, 171 (66.3%) patients with subnormal performances with respect to the same age range of healthy subjects were recruited for baseline assessment (Lau et al 2005). With 38 patients unable to participate in the subsequent training sessions, 133 remained and were allocated randomly to the control or exercise group

It is reported that no patients were lost to followup, although a further 38 people were excluded for being "unable to participate in the subsequent training sessions".
 
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Patients in the exercise group completed an intensive exercise program provided and monitored by the physiotherapists for 4–5 sessions a week (two sessions in the physiotherapy department) with 1–1.5 hours per session for 6 weeks.

RESULTS

Mean change 6-minute walk distance (m) Controls 614.3 + 20.7 = 635 ___ Exercise 590.7 + 77.4 = 668
Mean change Predicted VO2max (ml/kg/min) Controls 37.8 + 1.0 = 38.8 ___ Exercise 35.1 + 3.6 = 38.7

VO2 max was not actually measured, but was estimated based on a walk test and a step test, both of which have a volitional element. People could potentially push themselves harder if they were trying to show that they had improved, therapists could apply more encouragement at the end of the 6 weeks, and practice could increase speed.

There were no statistically significant differences in the two muscle strength measures (anterior deltoid and gluteus maximus) - this was not reported in the abstract.

SF–36 *** controls baseline + controls change *** exercise baseline + exercise change
No differences in mean change were reported as being statistically significant.
Each SF-36 measure is scored out of 100, and higher scores means better health.

Physical functioning ___ 71.1 + 3.7 ___ 69.6 + 3.7
Role physical ___ 35.7 + 14.6 ___ 26.8 + 14.4
Role emotional ___ 47.0 + 8.9 ___ 42.3 + 1.9
Bodily pain ___ 69.4 + -5 ___ 65.2 + 0
Social functioning ___ 61.1 + 14.2 ___ 59.5 + 12.9
General health ___ 46.6 - 2.5 ___ 51.6 - 0.76
Mental health ___ 64.0 - 0.3 ___ 67.9 - 1.7
Vitality ___47.5 + 2.5 ___ 51.2 + 1.3
 
This prospective, single (assessor)-blinded, controlled study has shown that a 6-week exercise training program for SARS survivors, conducted and supervised by a group of physiotherapists, could lead to a greater improvement in both cardiovascular and musculoskeletal performances.

The cardiovascular performance was measured by largely subjective measures. Although some measures of musculoskeletal performance improved more in the supervised exercise group, some weren't, even after intensive training. Given that the treatments were unblinded and there was a lot of therapist contact in the supervised exercise group, we would have expected those participants to report with a positive bias, but no measure of health reported by participants improved more in the supervised exercise group than it did in the control group.

This study does not constitute evidence of useful benefits.
 
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I'm aware I'm giving weight to subjective SF-36 results and discounting measures that might be regarded as objective. I think in this case it's ok.

As I've said, I don't think the walk test and step test are very objective. I consider myself significantly affected by my illness, but I don't think it substantially affects my 6-minute walk performance if I have rested before it. I think my performance would be affected by how motivated I was to do well though.

I don't think a measure of hand grip strength that didn't involve a lot of repeat measurement has much to do with my illness if I have rested before it.

An increase in SF-36 items in an unblinded trial certainly may be the result of the placebo effect. But, this study found a lack of an increase in SF-36 items over the control group in an unblinded trial where participants had been specifically selected for their motivation and cooperation and where they had had 6 weeks of contact with therapists. The biases were loaded in favour of the supervised exercise therapy group reporting better SF-36 increases than the controls. But, even so, they didn't.
 
I remember some time ago an article featuring one of the clinical lead in Toronto who worked on rehabilitation programs for SARS patients. He was so sad that he couldn't help. With tears in his eyes, said that he'd do it all over again because it was worth it. He wanted to help them so much. But even though he didn't, he'd do the same useless stuff today. I think it was about Long Covid, and IIRC he still thinks it's a good idea.

The Aristocrats
Evidence-based medicine
 
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