Table 3

Relative risk of death from lung cancer: studies comparing annual chest radiography with annual chest radiography plus 4 monthly sputum cytological examination

No randomisedNo of lung cancer deaths
StudyInterventionControlInterventionControlRelative risk (95% CI)
*With the random effects model the pooled results were 0.88 (95% CI 0.73 to 1.06)
Memorial Sloan15496850721151200.98 (0.76 to 1.26)
Johns Hopkins17522651611411730.80 (0.65 to 1.00)
Total10194102332562930.88 (0.74 to 1.03)*