We adopted log-binominal regression models rather than logistic regression models as the prevalence of outcome events (change in smoking behavior after marriage) was relatively large [ 24, 25].
First, the prevalence of events identified as being of international public health concern might not reflect the prevalence of events truly reported to WHO.
We estimated crude prevalence of events per group (with 95% confidence interval) and crude prevalence rate ratios for all comparisons.
Group size should be adjusted under conditions where the prevalence of events is low such that the expected number of events in each group should be greater than one.
As discussed by the authors of the study, the use of these codes probably led to considerabe underestimation of the prevalence of events, and thus the burden of disease [ 16].
Comparing the LVF group and the without LVF group in their admission we observed a grater prevalence of events (P = 0.02) in the first group, relative risk = 3.16 (95% confidence interval = 2.28 4.04).
In real life conditions, events least likely to be of international public health concern would have been excluded even before being submitted to the decision instrument, which would increase the prevalence of events of international public health concern in events submitted to the decision instrument and consequently the PPV.
There were no differences between the various sub-groups in either age at start of PA previously in life or prevalence of events of PA, mean number of events of PA, and starting time of PA after delivery (Table 1, see additional file 1). Figure 1 shows the starting time of PA after delivery for all respondents.
The use of different definition did not modify the fact that iv NAC did not protect against contrast nephropathy, but altered the prevalence of events in our population as it could range from 16 to 24.5% depending on the definition used.
Our task is not to judge between these processes, but to help practitioners more efficiently gather together information that would help them use the process they deem most appropriate for a given task (e.g., prior reports and the prevalence of events in exposed and non-exposed patients).
