Study to Analyze the Risk Factors Associated With Pertussis/Whooping Cough Infection Among Infants

Primary outcomes

1. Assessment of claim identified pertussis/whooping cough

   Time frame: Up to one year

   The endpoint(s) for the primary objective are the odds ratios associated with factors modelled in a logistic regression (conditional logit model) where the outcome is the diagnosis of pertussis/whooping cough. Demographic, economic and clinical risk factors available in the administrative claims database and potentially associated with pertussis/whooping cough infection will be estimated. Covariates will be determined based on clinical rationale and statistical significance.

2. Assessment of health care resource utilization

   Time frame: Up to one year

   Health care resource utilization (e.g. ambulatory visits, emergency department visits, inpatient hospitalizations, length of stay) will be calculated for infants with a reported diagnosis of pertussis/whooping cough stratified by the number of DTaP vaccinations received prior to infection.

3. Assessment of health care costs

   Time frame: Up to one year

   Health care costs will be computed as the combined health plan and patient paid amounts in the post-index period. Costs will be calculated as a total costs, medical costs, pharmacy costs, ambulatory costs, emergency costs and other costs and split by those occurring prior to the index date and those in the follow-up period. Costs will be adjusted to 2012 U.S. dollar values using the Medical Care Consumer Price Index.