Prevalence is not enough: the importance of appropriateness of contraceptive method in evaluating unmet need for contraception.

Data from the 1991-92 Peru Demographic Health Survey (DHS) containing representative samples from 13 administrative regions were used to compare unmet need for appropriate contraception with unmet need for any contraception. The analyses were limited to women in sexual unions who were habitual residents of the households. The categories of reproductive preference were: 1) women who wanted a child soon; 2) women who wanted to wait before their next child; and 3) woman who did not want any more children. Appropriate contraception for women in category 1 was either no method or any temporary method. In category 2 any temporary method was appropriate; and in category 3 appropriate methods included vasectomy the IUD oral contraceptives or contraceptive implants or injections. At the national level total demand for contraception increased by 3.5%. Loreto and Inka with general fertility rates of 176 and 175 showed a 7% increase in total demand. Arequipa with a general fertility rate of 92 had a 2% increase in total demand and Luna with a general fertility rate of 69 showed a 1.5% increase. The analysis was repeated with observed pregnancy rates which estimated current contraceptive behavior. Age-specific pregnancy rates were calculated. The total pregnancy rate was calculated as for the total fertility rate by adding up the age-specific rates and multiplying by 5. The partial pregnancy ratio was calculated by dividing the combined pregnancy rates above age 35 by the total pregnancy rate. Both measures of unmet need showed higher correlations with the partial pregnancy ratio than they did with the partial fertility ratio but only the correlation between the partial pregnancy ratio and unmet need for appropriate contraception was statistically reliable. The 2 models indicated that unmet need for any contraception correlated with overall fertility levels but not with degree of fertility control. In contrast unmet need for appropriate contraception more reliably predicted degree of fertility control and provided a sensitive evaluation indicator of family planning program effectiveness.