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Table 2 Limitations of published placebo-controlled antibiotic trials in acute exacerbations of chronic obstructive pulmonary disease

From: The problems of meta-analysis for antibiotic treatment of chronic obstructive pulmonary disease, a heterogeneous disease: a commentary on Puhan et al

Limitation of study design Potential consequences
Small number of subjects Type 2 error
Subjects with mild or no underlying chronic obstructive pulmonary disease included Diminished overall perceived efficacy of antibiotics
Non-bacterial exacerbations included Type 2 error
End-points compared at 3 weeks after onset Spontaneous resolution mitigates differences between arms
  Clinically irrelevant as most decisions about antibiotic efficacy are made earlier
Speed of resolution not measured Clinically relevant end-point not assessed
Lack of long-term follow-up Time to next exacerbation not assessed
Antibiotic resistance to agents with limited in vitro antimicrobial efficacy Diminished overall perceived efficacy of antibiotics
Poor penetration of antibiotics into respiratory tissues Diminished overall perceived efficacy of antibiotics
Concurrent therapy not controlled Undetected bias in use of concurrent therapy
  1. Reproduced with permission from Sethi [10].