Figure 2From: Second hand smoke exposure and the risk of invasive meningococcal disease in children: systematic review and meta-analysis Smoking by any smoker in the household and the risk of invasive meningococcal disease: subgroup analysis by methodological quality. Squares indicate the odds ratio and bars represent 95% confidence intervals (CI). Odds ratios more than one indicate smoke exposure in the household increases the risk of invasive meningococcal disease in children.Back to article page