Chest radiograph in acute respiratory infections: Cochrane systematic review
Chest radiography is widely used during the management of acute lower respiratory infections, but the benefits are unknown.
To assess the effects of chest radiography on clinical outcome in acute lower respiratory infections.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1), MEDLINE (1950 to January 2007) and EMBASE (January 1976 to February 2007).
Randomised or quasi-randomised trials of chest radiography in acute respiratory infections.
Data collection and analysis
Both review authors independently applied the inclusion criteria, extracted data and assessed trial quality.
We identified two trials. One, of 522 outpatient children (and performed by the review authors), found that 46% of both radiography and control participants had recovered by seven days (relative risk (RR) 1.01, 95% confidence interval (CI) 0.79 to 1.31). Thirty-three per cent of radiography participants and 32% of control participants made a subsequent hospital visit within four weeks (RR 1.02, 95% CI 0.79 to 1.30) and 3% of both radiography and control participants were subsequently admitted to hospital within four weeks (RR 1.02, 95% CI 0.41 to 2.52). The other trial involving 1502 adults attending an emergency department found no significant difference in length of illness, the single outcome prespecified for this review (mean of 16.9 days in radiograph group versus 17.0 days in control group, P > 0.05).
There is no evidence that chest radiography improves outcome in outpatients with acute lower respiratory infection. The findings do not exclude a potential effect of radiography, but the potential benefit needs to be balanced against the hazards and expense of chest radiography. The findings apply to outpatients only.
Swingler George H, Zwarenstein Merrick
Chest X-rays in the treatment of acute respiratory infections
Chest X-rays are often used to try and determine whether a person has pneumonia. But it was not clear whether this helps the person recover faster. Two trials were found. One trial tested chest X-rays in 522 children who had symptoms for less than two weeks and were not so ill they had to be in bed. The other was in 1502 adults attending an emergency department who had symptoms for less than a month. Neither adults nor children who were X-rayed recovered more quickly than those who were not. Adverse factors such as cost and the possible harms of radiation were not measured in either trial. Neither trial included people admitted to hospital, or children with symptoms lasting longer than 14 days, or adults with symptoms longer than one month.
Implications for practice
There is no evidence that chest radiography improves clinical outcome in ambulatory children aged over two months or in adults with clinically suspected acute lower respiratory infection. The findings do not exclude a potential effect of chest radiography, but the potential benefit needs to be balanced against the hazards and expense of chest radiography. These findings do not necessarily apply to people admitted to hospital, in whom the scope and severity of disease may differ greatly. This review does not address radiograph use in children with symptoms lasting longer than 14 days, or adults longer than one month.
Implications for research
High quality evidence from randomised controlled trials is needed to establish the effectiveness, or lack thereof, of chest radiography in acute respiratory infections in clinical subgroups of both adults and children. These subgroups include people admitted to hospital, although the ethical issues will need careful consideration. Clinically important outcomes, including time to recovery and the occurrence of clinical complications should be assessed.