UTILITY OF PERCENTAGE OF BIRTHS TO TEENAGERS AS A SURROGATE FOR THE TEEN BIRTH-RATE

Objectives. The teen birth rate is commonly used in comparing regional variation in teen pregnancies, but local teen birth rates are not alw ays available. In this study the percentage of all births that are to teens was evaluated for its utility as a surrogate for the teen birth rate. Methods. Rank correlation and sensitivity and specificity analys es were used. Results. The Spearman rank cor relations between percent age of teen births (PTB) and teen birth rate (TBR) were .995,.906, and .841 for the 3 age groups suggesting that it may be reasonable to emp loy PTB to prioritize zip codes. Zip codes with upper quartile levels of percentages of teen births identified zip codes with upper quartile levels of TBR with a sensitivity of 83.8%, 68.8%, and 65%; a false-po sitive rate of 2.1%, 8.6%, and 10%; and a positive predictive value of 89.3%, 67.6%, and 67.5% for the age groups 10 through 14, 15 through 17, and 18 through 19 years. Conclusions. The percentage of births to teens is a useful surrogate for teen birth rate in California, especia lly among younger teenagers.