In-hospital physiotherapy improves physical activity level after lung cancer surgery: a critical appraisal
Posted on 9th May 2019 by Sophie McAuliffe
This blog is a critical appraisal of the following randomized controlled trial: In-hospital physiotherapy improves physical activity level after lung cancer surgery: a randomized controlled trial.
Lung cancer is the most prevalent cause of cancer death worldwide, as stated by Smith et. al (2008). Medical management includes chemotherapy, radiotherapy and surgical resection. The role of physiotherapy in lung cancer patients focuses on exercise therapy and breathing techniques. Granger (2016) reveals research is primarily based on these interventions. Physiotherapy is routinely offered to patients following lung cancer surgery, however, effects of postoperative physical activity levels have not yet been explored.
What was the study?
The study aimed to investigate if in-hospital physiotherapy could improve physical activity and capacity levels in patients after lung cancer surgery. Recruitment of 132 participants due to undergo elective thoracic surgery for suspected or confirmed lung cancer were screened against eligibility criteria, with 25 excluded for various reasons.
107 participants were randomly assigned to the intervention (n=54) and control group (n=53). The intervention group received routine pre-operative information detailing mobilisation and breathing exercises. During the first three days following surgery, they received 20-30 minutes of physiotherapy inclusive of individualised mobilisation, range of motion exercises and instruction to walk as much as possible. They received instructions on breathing techniques including positive expiratory pressure, coughing and huffing. Patients who were still in hospital on the fourth day received treatment based on their status. The control group received no physiotherapy intervention pre or post-operatively.
The primary outcome, physical activity level, was recorded using an Actigraph GT3X+ accelerometer. The secondary outcomes were physical capacity assessed by the six-minute walk test (6MWT), lung function measured by spirometry, pain intensity recorded measured by a numeric rating scale (at rest, while taking a deep breath, when coughing) and subjective degree of dyspnoea measured by the Medical Research Council (MRC) dyspnoea scale. Baseline measurements were recorded on the day of admission prior to surgery and on the fourth day after surgery, for those participants who were still at the hospital and could perform the tests.
According to the study, in-hospital physiotherapy improves physical activity levels for the first three days after surgery. No significant difference was recorded in lung function, pain intensity or subjective level of dyspnoea.
What were the strengths and weaknesses of the study?
The CASP RCT tool will be used to evaluate results and determine the validity, reliability and treatment effect.
Due to the nature of the treatment, the physiotherapists providing the intervention could not be blinded. In an attempt to minimise bias and increase internal validity by allocation concealment, assessments were carried out by physiotherapists who were blinded to group allocation.
Patients presented with similar pre-operation characteristics in relation to age, BMI and baseline recordings of outcome measures. Granger (2016) reveals lung cancer is the most common diagnosis in males and fourth in females. In this study, the male to female ratio differed between groups (male/female, male %), intervention n=50 (28/22, 56%), control n=44 (17/27, 39%), p value 0.97. With the alpha level set at < 0.05 to be considered statistically significant, further research is required to determine if these results are due to chance.
From the intervention group, n=4 were discharged before the third post-operative day and n=24 were unable to perform the tests for reasons including pleural drainage insertion. The control group included n=6 lost to follow-up due to discharge before the third postoperative day, n=3 lost due to accelerometer technical error and n=16 unable to perform tests. Evidently, there was a significant loss to follow-up especially in the control group. For the results to be considered statistically significant, an intention-to-treat analysis should be carried out with 53 patients per group. The sample size would need to be larger than the relatively small 107 participants with a more heterogeneous population considering co-morbidities, lifestyle factors and previous malignancy.
Different surgical methods were performed dependant on the surgeon which did not affect outcomes. However, differences in duration of surgery and length of stay were revealed. Correlation between duration of pleural drainage insertion and hospital stay reads p < 0.001 so we can take this as statistically significant.
We refer to the 95% confidence interval when deciding to apply therapy to patients in future practice. The accelerometer recordings and physical activity levels based on steps and counts per hour at days two and three post-surgery are the only significant values. Patients in the treatment group achieved a mean 49 steps, 2010 counts per hour versus the control group achieved a mean 37 steps, 1629 counts per hour. Aadland (2015) suggests accelerometers measurements to be collected over several days to ensure reliability in measuring physical activity.
Based on the results of this particular study, in-hospital physiotherapy improves physical activity levels in patients with lung cancer for the first three post-operative days. Therefore, physiotherapy could be beneficial for patients during the post-operative period. However, further research is required, ideally with a larger sample population and an even ratio of male to female, to determine if the treatment effect can be applied to the local population.