Systematic Review Scenario


Mary Ann O’Brien

You receive a referral for a 65-year-old woman with a diagnosis of chronic obstructive pulmonary disease (COPD). She tells you that her main problems are breathlessness, fatigue, and general weakness. She feels her quality of life has been getting worse because she is too tired to leave the house and visit friends and family. A friend has been to an in-patient exercise program in the hospital and she wonders if this type of program would help her. Together you formulate a question: “In a patient with chronic obstructive pulmonary disease, does an in-patient pulmonary rehabilitation program improve strength, endurance, and quality of life?”

You search MEDLINE using the terms ‘pulmonary rehabilitation’ and ‘chronic obstructive airways disease’ and find a promising systematic review.

Lacasse Y, Wong E, Guyatt GH, King D, Cook DJ, Goldstein RS. Meta-analysis of respiratory rehabilitation in chronic obstructive pulmonary disease. Lancet 1996;348:1115-9.

Read the article and decide:

  • Is the evidence from this systematic review valid?
  • Is this valid evidence from this systematic review important?
  • Can you apply this valid and important evidence from this systematic review in caring for your patient?

Completed Systematic Reviews Worksheet for Evidence-Based Physiotherapy Practice

Citation

Lacasse Y, Wong E, Guyatt GH, King D, Cook DJ, Goldstein RS. Meta-analysis of respiratory rehabilitation in chronic obstructive pulmonary disease.
Lancet 1996;348:1115-9.

Are the results of this systematic review of therapy valid?

Is it a systematic review of randomised trials of the treatment you are interested in?
Yes.
Does it include a methods section that describes finding and including all the relevant trials?
Yes.
Does it include a methods section that describes assessing their individual validity?
Yes.
Were the results consistent from study to study?
Consistent results for health related quality of life (dyspnoea, and control over CAL). Functional exercise capacity results showed heterogeneity that could not be explained by sensitivity analysis.

Are the valid results of this systematic review important?

Do these results apply to your patients?
Are your patients so different from those in the systematic review that its results can’t help you?
No
How great would the potential benefit of therapy actually be for your individual patient?
Method I: In the table on page 1, find the intersection of the closest odds ratio from the overview and the CER that is closest to your patient’s expected event rate if they received the control treatment (PEER).
In the systematic review, the authors report the minimum clinically important difference (MCID). This was defined, as the smallest difference perceived by the average patient.
Method II: To calculate the NNT for any OR and PEER:
$$ mathit{NNT} = frac{1-[mathit{PEER} times (1-mathit{OR})]}{(1-mathit{PEER}) times mathit{PEER} times (1-mathit{OR})} $$
Are your patient’s values and preferences satisfied by the regimen and its consequences?
Do your patient and you have a clear assessment of their values and preferences?
Yes
Are they met by this regimen and its consequences?
Yes
Should you believe apparent qualitative differences in the efficacy of therapy in some subgroups of patients?

Only if you can say “yes” to all of the following:

  • Do they really make biologic and clinical sense?
  • Is the qualitative difference both clinically (beneficial for some but useless or harmful for others) and statistically significant?
  • Was this difference hypothesised before the study began (rather than the product of dredging the data), and has it been confirmed in other, independent studies?
  • Was this one of just a few subgroup analyses carried out in this study?

Additional Notes

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Upper Abodominal Surgery – Periop physio decreases postop pulmonary complications

Clinical Bottom Line

Respiratory rehabilitation that includes at least 4 weeks of exercise training relieves dyspnea and improves control over COPD.

Citation

Lacasse Y, Wong E, Guyatt GH, King D, Cook DJ, Goldstein RS. Meta-analysis of respiratory rehabilitation in chronic obstructive pulmonary disease.
Lancet 1996;348:1115-9.

Clinical Question

In a patient with COPD, does an in-patient pulmonary rehabilitation program improve strength, endurance, and quality of life?

Search Terms

You search MEDLINE using the terms ‘pulmonary rehabilitation’ and ‘chronic obstructive lung disease’ and find a promising systematic review.

The Study

Systematic review of 14 RCTs of respiratory rehabilitation programs. The respiratory program for patients with a diagnosis of COPD, had to have been compared with conventional community care or other interventions that were unlikely to affect exercise capacity or quality of life.

The Evidence

Significant improvements were found for maximum exercise capacity, functional exercise capacity, and health related quality of life (HRQL). The pooled effect size for maximum exercise capacity was 0.3 SD units (0.1 to 0.6) and corresponded to 8.3 watts (2.8 to 16.5) on a cycle ergometer test. For functional exercise capacity, the pooled effect size was 0.6 SD units (0.3 to 1.0) corresponding to 55.7 meters (27.8 to 92.8) on a six minute walk test. For two aspects of HRQL (dyspnoea and mastery), the overall treatment effect was larger than the minimal important clinical difference, 1.0 (0.6 to 1.5) and 0.8 (0.5 to 1.2) respectively. The results for functional exercise capacity showed heterogeneity unexplained by sensitivity analysis.

Comments

Patients with multiple health problems were excluded from the trials. The most common exclusion criteria were ischaemic heart disease, heart failure, intermittent claudication, disabling musculoskeletal problems, and at home oxygen use.

Appraised By

Mary Ann O’Brien