March 2013,The Lancet; In The Lancet, Leontine Alkema and colleagues1 illustrate the usefulness of rigorous modelling to provide convincing estimates of health indicators when empirical data are patchy or non-existent. Their report presents by far the most complete country-specific information about trends between 1990 and 2010, with projections to 2015, in two key family planning indicators for married or cohabiting women: use of any contraceptive method (contraceptive prevalence) and non-use in women who want to avoid childbearing for at least 2 years (unmet need). Worldwide, contraceptive prevalence increased during this 20-year period from 55% to 63%, and unmet need decreased from 15% to 12%, but glaring disparities between countries remain. For example, in 2010, contraceptive prevalence was less than 20% in 23 countries (all in Africa) and unmet need exceeded 30% in 12 African countries and three in other regions. These estimates support the call at the 2012 London Summit on Family Planning for a focused effort to bring contraception to people in countries where its use is still confined to a minority.2
These two indicators respond to different agendas but are complementary. Contraceptive prevalence is the main determinant of fertility; typically, an increase of 15—17 percentage points in prevalence reduces fertility (and thus population growth) by one birth per woman.3 In the past 50 years, most governments in developing countries have enacted policies to reduce population growth through promotion of family planning as a part of development. However, in contrast to demographic targets for death reduction, targets for birth reduction have proved controversial because of concerns that couples might be pressured or even coerced into use of contraception.
By responding to the human rights agenda of reproductive choice, unmet need avoids these concerns. From its origins in the knowledge, attitude, and practice of family planning (KAP) surveys of the 1960s, which first identified the disjuncture between family size preferences and contraceptive use (the KAP gap), its measurement has been refined.4, 5 Unmet need has become a central rationale for donor support and advocacy and a crucial guide for interventions, culminating in its addition in 2007 as one of the indicators to monitor progress in target 5b of the Millennium Development Goals to “achieve, by 2015, universal access to reproductive health”.
Fortunately, although the fertility reduction and reproductive rights agendas differ in principle, they are mutually reinforcing.6 The historic mandate of family planning programmes has been to reduce unmet need through a decrease in the costs (broadly defined) of contraception, and reduction in unmet need is responsible for most of the increase in contraceptive use in the past few decades.7 Countries with high fertility rates also record high unmet need.
By 1990, contraceptive use was high and unmet need low not only in developed countries but also in Latin America and much of Asia. Thus, the main interest lies in the straggler areas: southern and western Asia and Africa. Progress since 1990 has been variable. Notable increases in prevalence and substantial falls in unmet need have occurred in western and southern Asia and in northern and southern Africa, but the most marked increase in use, from 12% to 33%, has taken place in eastern Africa, largely because of greater government commitment and improved community-based services.8 However, unmet need in this subregion has decreased only modestly, from 30% in 1990 to 26% in 2010, indicating that increased need, stemming from sharp reductions in desired numbers of children, has almost matched increased use.9
By contrast, progress in western and central Africa has been poor. Nigeria, the most populated country in sub-Saharan Africa, is typical. Contraceptive prevalence has risen from 7% to only 14% in 20 years and unmet need has remained static at 21%.1 Of greatest concern are the Sahelian countries of Chad, Mali, Mauritania, and Niger, where the combined population is projected to increase threefold, from 45·6 million in 2010 to 131·9 million in 2050,10 which presents an impossible burden for fragile ecosystems.
An estimated 146 million married women had an unmet need in 2010.1 Knowledge of methods and access to services are inadequate in some countries, but these are not the main reasons for the persistence of unmet need in most settings. In western and central Africa, ambivalence or even hostility towards contraception is a serious obstacle, but concerns about the perceived adverse health effects of particular methods are a more widespread problem.11
Expansion of services, especially in the form of community-based provision in rural Africa, is a priority, but equally important is the need to address social obstacles and health concerns through mass media and focused efforts to engage the support of religious and community leaders.
An important but neglected contributor to unmet need is the narrow range of methods used in many high-prevalence and low-prevalence countries (figure).12 For example, in India, female sterilisation accounts for two-thirds of all contraceptive use and effective reversible methods are rare. An unfortunate consequence is that the prevalence of short inter-birth intervals, which pose a threat to infant health and survival, has remained unchanged in the past 20 years.13 Conversely, in neighbouring Bangladesh, where most women use pills or injectable contraceptives, a pressing need exists for greater use of long-acting methods, such as intrauterine devices or sterilisation. In Bangladesh, most women have achieved their desired family size by 25 years of age.14
In sub-Saharan Africa, pills and injectables also dominate contraceptive use. Discontinuation of these two methods is common. Typically between 20% and 30% of women stop use within 1 year of starting because of side-effects or health concerns.15 In this region, an increasing proportion of unmet need stems from women who have unsuccessfully tried one or both of these two methods, but do not have alternative options. This trend emphasises the potentially huge benefit that could be achieved by increasing the range of methods available to, and used by, women, thereby better meeting their reproductive rights and needs. The success of efforts to increase contraceptive use and reduce unmet need can now be monitored by regular updates of the modelling devised by Alkema and colleagues.