Table 3.

Summary of modelling characteristics

	Number of studies (n = 33)
Unit of outcome data
Daily	3
Weekly (including bi-weekly)	13
Monthly (including bi-monthly)	16
Yearly	1
Regression models
GLM (Poisson, quasi-Poisson, negative binomial)	28
GAM (Poisson, negative binomial)	3
Mixed models	2
Control of seasonality and long term trend
Some adjustments were included in the model	25
No adjustments / not described	8
Autocorrelation
Examined / included parameters to control autocorrelation	21
No specific measures / not described	12
Lag effects of exposure
Lag effects of whether variables were assessed	28
No lag effect assessments	5