There is overwhelming evidence that the majority of those with malaria, particularly in Africa, do not get antimalarials effectively. This applies to all antimalarial classes, not just to ACT, and is, therefore, a major systems failure. Evidence from across Africa demonstrates that there are multiple steps at which delivery of antimalarials may fail. Evidence from Asia and South America is sparser, but lessons from Asia may be important as the burden of disease in some parts of Africa reduces. The first step is that many children and adults with febrile illness that could be malaria are treated at home, often with ineffective treatment [
5‐
7]. Of those who are taken for some form of assessment, the majority are taken to the informal sector [
8]. What constitutes the informal sector varies for each local setting and can include traditional healers, chemical or medicine sellers or small shops that sell drugs or other unregulated providers. Of those who do present to the informal sector, the proportion receiving an antimalarial varies. In most informal settings there are no diagnostic facilities available and targeting is largely random: in some, less than 20% of those with symptoms compatible with malaria are given an antimalarial [
9]; elsewhere, it can be as high as 75%, although ineffective treatment with monotherapy is common [
10] and prescriptions may be in sub-therapeutic doses, prescribed by unqualified staff [
11,
12]. Of the minority who do access formal health care, malaria is the default diagnosis and an antimalarial will usually be prescribed [
13], although this will not necessarily be an effective antimalarial: non-ACT antimalarials continue to be prescribed in the public sector in areas where the local alternative monotherapy has convincingly failed [
14]. Once ACT use becomes the norm the proportion treated with ineffective drugs tends to decline [
15,
16]. The reasons for this are complex [
17], and simple solutions are unlikely to be effective. The continuing use of failed drugs is probably even more common in the private sector where price is a major issue, and the continuing use of artemisinin monotherapy is a serious worry for the development of drug resistance [
18].
There are multiple barriers to accessing formal healthcare and unfortunately these are likely to fall most on the poorest, who, in the majority of cases, are those most likely to have malaria [
19]. These barriers include perceived quality of care [
20], lack of knowledge [
21,
22], distance from health services [
23], transport costs, treatment costs [
22,
24], difficulties in finding care for other children if the parent or guardian accesses care, opportunity costs (which may make up the majority of formal healthcare episode costs to the family) and, sometimes, difficulties for mothers in getting permission and funds to attend health centres [
25‐
28]. Even where drugs are not subsidized, the indirect costs of care exceed the direct costs [
29]; free drugs do not solve this problem. Local conceptualization of disease also affects the decision to use formal healthcare [
30‐
32].