Figure 1.
Flow diagram of screened, excluded, and analysed publications.
Figure 2.
Methodological quality of included randomized controlled trials: review authors’ opinion on each item of bias risk based on Cochrane handbook.
“+”, “-” or “?” reflected low risk of bias, high risk of bias and uncertain of bias respectively. ALLHAT-LLT: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial.
Figure 3.
Forest plot: overall meta-analysis of statin use and lung cancer risk.
Squares indicated study-specific risk estimates (size of square reflects the study-statistical weight, i.e. inverse of variance); horizontal lines indicate 95% confidence intervals; diamond indicates summary relative risk estimate with its corresponding 95% confidence interval.
Figure 4.
Forest plot: long-term statin use and risk of lung cancer.
Squares indicated study-specific risk estimates (size of square reflects the study-statistical weight, i.e. inverse of variance); horizontal lines indicate 95% confidence intervals; diamond indicates summary relative risk estimate with its corresponding 95% confidence interval.
Figure 5.
Forest plot: cumulative meta-analysis of statin use and lung cancer risk.
Figure 6.
Funnel plot for publication bias in the studies investigating risk for lung cancer associated with use of statins.
No publication bias was observed among studies using Begg’s P value ( P = 0.56) and Egger’s ( P = 0.59) test, which suggested there was no evidence of publication bias.