Discussion
NNT≈, dyspnea, pain, lung cancer, cough, EPS, muscle wasting
ADVERSE EVENTS, COVID-19 PNEUMONIA, DISEASE, VIRAL PNEUMONIA, LUNG CANCER, ADVERSE EFFECTS, MUSCLE WASTING, INFLUENZA
According to our knowledge, this study is the first RCT to evaluate the efficacy of the PPT through comparison with a control group on non-intubated hospitalized patients with severe COVID-19 pneumonia. Our designed interventions seem to be safe and effective without serious adverse effects.In general, the results show that participants’ pO2, PH, 3MWT, and level of dyspnea values were improved in the PPT group than the basic care group after adjustment of each measurement to the baseline measure. Spo2 was also higher in the PPT group than the basic care group clinically significant after three days [After one-month follow-up, PPT was associated with higher HRQOL in role limitation due to physical health domain (NNT≈ 3) with a moderate effect size. Also, patients in PPT group presented higher score in body pain domain of SF-36 instrument than basic care group (NNT≈ 2) after three months with a large effect size. Patients with COVID-19 suffer from significant physical and psychological impairments that impact their HRQOL; Therefore, interventions improving HRQOL like rehabilitation should be considered in their management [Allocated participants to the PPT group had a 20% and 25% lower one-month and three-month mortality rate than the basic care group, respectively. The NNT analysis shows that PPT kept alive one out of five patients until one month. However, the results of logistic test of one-month mortality rate is not statistically significant. Based on the NNT analysis, PPT can keep alive one out of four patients until three months. A similar finding was reported in patients after lobectomy after lung cancer by Çınar et al. (2020). They showed that patient received postoperative respiratory physiotherapy had no mortality after 30 days, while patients received standard postoperative care had 8% 30-day mortality rate [Adjusting each variable to its baseline measurement increased partial eta2> 10% than crude analysis, suggesting that even small differences of each measured outcome can change the results. A similar effect was not found about baseline Spo2.There are currently some published studies with different levels of evidence, mostly review of investigations about PPT and other cases of viral pneumonia such as influenza, expert opinions, and consensus statements recommended how and when to use PPT for patients with different stages of COVID-19 pneumonia. Some researchers, physiotherapy, and rehabilitation experts have recommended PPT as an effective rehabilitative intervention for patients with all stages of COVID-19 pneumonia [About 34% of patients with COVID-19 pneumonia suffer from EPS [Our used PPT program had three main characteristics. First, choose the type of PPT technique(s) based on the patients’ signs and symptoms. We used IHT with emphasis on diaphragmatic breathing and educated them on how to cough and breathe properly, but ACTs were only applied to patients with EPS signs and symptoms. Second, we also defined some criteria for holding the intervention to get better safety. Third, we set a mild aerobic exercise in addition to chest physiotherapy to prevent muscle wasting and aerobic deterioration, which are seen in patients with COVID-19 [Our research had some limitations which should be considered in future studies. First, we selected the sample size as MCID of Spo2 as the primary outcome measurement, but this number seems to have not enough power for other variables. For example, allocated participants in the PPT group had a 20% lower mortality rate than the control group. This RD seems to be influential; however, the results of logistic tests in the mortality rate did not reach a statistically significant level. Therefore, further investigations with a larger sample size are highly suggested evaluating safety and efficacy of PPT in patients with COVID-19. Second, we only recruited participants from a single center. Now, different centers have particular therapeutic guidelines that can impact the results of PPT. The applied interventions in this study with three-day duration, no need for specific tools and, low risk of adverse events suggest the feasibility of multi-center investigations on PPT effectiveness and safety on hospitalized patients with COVID-19. Third, we only recruited patients with a severe stage of COVID-19. Based on the mentioned possible mechanism, PPT may be more effective if to be started before disease severity reaches to severe phase even when the symptoms appear; therefore, future researchers are recommended to investigate the efficacy of PPT in patients with mild and moderate stages of COVID-19. Fourth, as participants of this study were from different cities, we could not re-assess their respiratory functions, aerobic capacity, and level of dyspnea. It is highly recommended that future researchers follow the objective pulmonary functions up to after patients’ discharge after applying PPT during the hospital stay. Fifth, the ITT analysis was performed only for categorical data while the primary outcomes were continuous. Although there was 7.5% attrition in the samples after three days, the readers should be aware of this point.