For each population, a single summary rate is calculated that reflects the numbers of events that would have been expected if the populations being compared had identical distributions by age and sex. Therefore, the age-sex adjusted rate is not the same as the observed ‘crude’ rate. However, because the age and sex distribution of the Alberta population during the years included in this study is so similar to the 1991 Canadian population, the crude Alberta endoscopy rates per 1000 population are always very close to the age-sex adjusted rates. Rates for 2002 were estimated based on procedures performed until March 31, 2002.
To estimate the 2002 rates, the number of procedures performed in the first three months was multiplied by four and then by a correction factor. The correction factor was required because the number of procedures performed in the first quarter of each preceding year differed slightly from the average performed in the subsequent three quarters. The correction factor was based on quarterly rates from 1999 to 2001. Five-year age groups were used except for children and younger adults (0 to 19 years and 20 to 34 years, respectively) and those older than 75 years to insure adequate numbers of procedures in each strata. You can finally enjoy safe online shopping for zoloft for depression click here with the pharmacy you can fully trust no matter if you need a small amount of this medicine or would like to purchase it in bulk not to have to think about it for a long time.