Duration of treatment was calculated from dates of claimed prescriptions and the dispensed quantity of insulin agents (international units (IU)) and number and strength of tablets for oral glucose-lowering agents, respectively.
Miller argued that there is an "inherent difficulty in gathering and assessing evidence in respect of a period earlier than the date of claim".
The resulting file included the following information for each CAD claim: date of claim, claim number, and gender, breed and date of birth of the animal.
We compared exposure on the basis of information recorded in the database without the possibility of ascertaining whether the dates of benzodiazepine claims corresponded to their actual consumption.
Variables available through MarketScan include demographic data (sex, birth year), enrollment dates, dates of specific claims, 3-digit zip codes, patient age, and International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes for healthcare claims.
The first prescription claim during this period was identified as the index claim, and the date of this claim was the index date.
Each closed claim record included the license number of the physician involved, whether an indemnity payment was made, and, if so, payment size, and dates of alleged injury, claim filing, and claim closure.
As the median duration of statin prescription in the database was 28 days, a patient would be enrolled if there was no existing claim of a statin prescription within 3 months after the first date of any claim.
Acute LBP has a different prognosis than chronic LBP (duration >12 weeks), 19 and we excluded all claims in which the number of days between the accident date and registration date of the claim was greater than 30 days.
We obtained the dates (year and month) of claims issued for the study subjects together with the diagnosis and treatment codes.
