Contraceptive method skew and shifts in method mix in low- and middle-income countries.

Context: Method mix-the percentage distribution of contraceptive users in a given country, by method-is one measure that reflects the availability of a range of contraceptive methods. A skewed method mix-one in which 50% or more of contraceptive users rely on a single method-could be cause for concern as a sign of insufficiency of alternative methods or provider bias. Shifts in method mix are important to individual countries, donors and scholars studying contraceptive dynamics.

Methods: To determine current patterns and recent changes in method mix, we examined 109 low- and middle-income countries. A variety of statistical methods were used to test four factors as correlates of skewed method mix: geographic region, family planning program effort index, modern contraceptive prevalence rate and human development index. An assessment of changes in reliance on female and male sterilization, the IUD, the implant and the injectable was conducted for countries with available data.

Results: Of the 109 countries included in this analysis, 30% had a skewed method mix-a modest decrease from 35% in a 2006 analysis. Only geographic region showed any correlation with method skew, but it was only marginally significant. The proportion of users relying on female sterilization, male sterilization or the IUD decreased in far more countries than it increased; the pattern was reversed for the injectable.

Conclusion: Method mix skew is not a definitive indicator of lack of contraceptive choice or provider bias; it may instead reflect cultural preferences. In countries with a skewed method mix, investigation is warranted to identify the cause.