Trends in the Contraceptive Method Mix in Low- and Middle-Income Countries: Analysis Using a New ‘‘Average Deviation’’ Measure

This limited range of user options constrains total contraceptive use, leading to unplanned pregnancies and births or abortions. Previous analyses of method mix distortions have focused on countries where a single method accounts for more than half of all use, known as the 50% rule. A new measure, the average deviation (AD) of method shares around their own mean, is introduced to analyze trends over time in the distribution of users across 8 contraceptive methods. This measure is used in conjunction with total contraceptive use to give a more complete and programmatically useful picture of trends over time. The AD values can range from 0 to 21.9, with most values ranging from 6 to 19, and an interquartile range of 8.6 to 12.2. Using the AD measure, 15 countries are identified where the method mix has evolved from a distorted one to a better balanced one, with AD values declining, on average, by 35% over time. Countries show disparate paths in method gains and losses toward a balanced mix, but 4 patterns are suggested: (1) rise of one method partially offset by changes in other methods, (2) replacement of traditional with modern methods, (3) continued but declining domination by a single method, and (4) declines in dominant methods with increases in other methods toward a balanced mix. Regions differ markedly in their method mix profiles and preferences, raising the question of whether programmatic resources are best devoted to better provision of the well-accepted methods or to deploying neglected or new ones, or to a combination of both approaches. Exclusive attention to the contraceptive method mix, by itself, can give misleading results, since the same mix may prevail at both low and high levels of total use. The increase in injectable use has modified the method mix in eastern and southern African countries and elsewhere, as reviewed by Adetunji and by Sutherland et al. The injectable increase has been mainly additive to the prior level of total use, rather than substituting for other methods. While its popularity has raised total use in many settings, it is a short-acting method, and questions still remain about the frequency of its discontinuation and switching to other methods. A poor method mix can prevail at both low and high levels of contraceptive use. The aim is not to prescribe a specific ideal method mix but to generally increase access to a wider variety of method choices. When the current mix is augmented by access to an additional method, total use tends to rise. Asian examples were noted by Freedman and Berelson, who estimated that adding 1 method to the mix would increase total use by about 12 percentage points.