Data on household expenditure complement those from other sources. Such data provide insights into both utilization patterns and the level of private out-of-pocket expenditure.
At the individual and household level, drugs represent the major out-of-pocket expenditure on health. A survey from Mali found that 80% of household expenditure on health was for modern drugs, 13% was for traditional medicine, 5% was for provider fees, and 2% was for transportation costs . In Côte d'Ivoire and Pakistan more than 90% of household health expenditure was related to drugs . Drugs or traditional products represent 62% of financial costs per treatment episode in Burkina Faso, with 17% for provider fees and 21% for transport and other living expenses incurred while seeking care .
Among 14 countries of Latin America and the Caribbean, drugs represented 35% of direct private expenditures on health. Figures ranged from slightly under 15% in the Cayman Islands and Uruguay to 44% in Peru, 45% in Guatemala, 46% in Colombia and 47% in El Salvador .
Household expenditure on drugs is closely tied to household income. In Ghana, for example, annual per capita drug expenditure varied from US$ 1.45 per person in the lowest-income households to $ 3.32 in middle-income households to $ 8.50 in the highest-income households .
Self-medication with privately purchased drugs often represents the most common treatment after home remedies. Household surveys indicate that drugs purchased from local drug sellers or pharmacies are used to treat approximately 53% of illness episodes in Burkina Faso (Figure 2). In an urban setting in Sri Lanka nearly 64% of the first actions taken by households in treating an illness were self-medication with western or traditional drugs (Figure 3). Studies on general and low-income populations in Kenya , Nepal , Rwanda , Thailand  and elsewhere [1,55] show similar high rates of medication with drugs acquired in the private sector. Even for potentially life-threatening illnesses such as malaria, self-medication through privately purchased drugs is common in both Africa and Asia [39,86].
Thus, at the household level as well as at national level, private purchase of drugs plays a major role in many countries, even for low-income populations.
Figure 2. Percentage distribution of household health-care-seeking behaviour, Burkina Faso 
Figure 3. Source of care for acute illnesses in Sri Lanka