The model behind perceived ADRs: the ‘hot and cold’ theory in Latin America
In Latin America the ‘hot and cold’ theory permeates popular models of health and illness. Derived from humoral theory, it was brought to America by the Spanish and Portuguese during colonial times and remained the dominant paradigm in medicine until its decline in the nineteenth century [
10,
11]. While it is uncertain whether these imported concepts of humoralism converged with similar autochthonous concepts or whether they were newly introduced to local health and illness models, it is clear that these principles were well integrated into the local world-views [
12]. However, several authors have pointed out that in Latin America, the ‘hot and cold’ theory is more dynamic and pragmatic than it was in Europe [
13,
14].
It is misleading to describe the ‘hot’ and ‘cold’ principles as a dichotomy because the theory refers to a
continuum with different
grades rather than clear-cut categories [
10]. Even in historical accounts, in the early eighteenth century, Brother Pedro de Montenegro [
15] remarked that the pairs of ‘hot/cold’ and ‘dry/wet’ qualities are each divided into four grades, from least to most, with the first being the most benign, and the last the most dangerous grade. Current popular models include intermediary categories of ‘fresh’ and ‘warm’ which, applied to drugs, plants, food, and beverages, are very important for treatment. By understanding the ‘hot/cold’ system as a
continuum, an illness can
transmute from one state to another [
16]. Adding up hot elements, even gradually and with small increments of heat, may finally lead to pathological
excess, like the last straw that breaks the camel’s back.
Arroyo Laguna and colleagues [
17] reported similar results from Peru where respondents mentioned that intake of hot foods, combined with environmental heat and heavy workload produced illness. Following the same logic, Logan’s study in Guatemala [
18] described the perceived detrimental effects of an excess of ‘cold’ when a ‘cold’ illness is treated with a ‘cold’ drug like penicillin. To regain health one has to restore the bodily balance: a ‘cold’ illness needs to be balanced with warm beverages, baths, medicines, and foods. Vice versa, a ‘hot’ illness requires to be cooled down with cold beverages, baths, medicines, and foods.
A sudden change from ‘hot’ to ‘cold’ or vice versa can provoke a ‘shock’. For instance, passing from a hot to a cold place, exposure to rain while sweating at work, a cold bath after exposure to the sun are activities that are perceived to cause illness, as a result of the ‘shock’ produced in the body. To avoid this, the body needs to be
gradually accommodated, for example, by first wetting one’s body before entering a hot or cold bath. ‘Cold’ and ‘hot’ must harmonize in order to produce a ‘temperate’ physical and moral balance and to achieve organic and emotional well-being [
14].
Why re-imagining treatment adherence from people’s perspective matters—the hot and cold theory in the context of malaria elimination
Although intensive community-based interventions have shown substantial improvements [
19,
20], adherence remains problematic even when drug supply is good [
21]. Besides structural, behavioural and other relevant factors that may hinder adherence, social representations of medicines play a key role. Studying perceived efficacy and side effects of anti-malarials in Tanzania, Kamat [
22] found that the cultural and social meanings attributed to drugs, i.e. cultural constructions of certain brand names and the perceived efficacy of different anti-malarials administered at public health facilities have a major impact on the health seeking itineraries of malaria patients. Public, free of charge treatments at local health facilities are not always preferred options precisely because of perceived drug efficacy and the cultural constructions of certain drugs [
21,
22].
In Iquitos, an unexpectedly high percentage of respondents reported to have experienced ADRs, namely ‘shocks’ (70 %) and ‘allergies’ (61 %). These ADRs were seen as the principal reason for abandonment of malaria treatment. The importance of perceived adverse effects was also a main reason for non-adherence in a study carried out in the province of Esmeraldas in Ecuador, in which adherence was estimated at 65.9 % based on interviews with clinically confirmed vivax and falciparum malaria patients [
23]. A qualitative study in Piura and Tumbes in Peru also cited the quick lessening of symptoms and the perceived adverse effects of treatment as the main elements for diminishing adherence [
24].
As health in the Peruvian Amazon is understood to be a balance between ‘hot and cold’, intake of ‘hot’ anti-malarials needs to be compensated by other components (diet, herbal remedies, baths, etc.) that restore health. The local construction of ADRs is part of this holistic perspective, which does not take drug reactions per se into consideration, but integrates them into a system of excesses and contrasts of ‘hot’ and ‘cold’. This local model includes five principles that have practical implications for adherence: (i) If treatment is abandoned, the illness remains ‘dormant’. Eating pork or drinking alcohol increases the risk that malaria ‘comes up’ or ‘relapses’; (ii) the ‘hot’ quality of anti-malarials poses a risk of ‘shock’, ‘allergies’, and other adverse reactions; (iii) this risk increases substantially if the patient ingests food, drinks, medicinal plants, or other remedies considered ‘hot’ (following the logic of ‘excess’) or ‘cold’ (following the logic of ‘contrast’), if the patient performs activities which ‘overheat’ the body, or if he gets exposed to excessive heat or sudden cold; (iv) the risk is reduced by tempering the body with ‘refreshing’ teas, foods, drugs, or baths; and (v) the person’s constitution increases or reduces the risk to suffer from adverse reactions.
The implications of the local model for adherence can be two-sided. While it is true that the ‘hot and cold’ theory can prompt patients to interrupt treatments, the logic of balance that underlies the theory permits re-imagining treatment beyond dominant images in malaria interventions. Current approaches are grounded in the war metaphor (the war or the fight against malaria) and focused on biomedical-technological solutions [
25], which make anti-malarial campaigns pathogen and vector-centred. The implications of the war metaphor as used in the malaria field, are that the target is an objectified disease, anti-malarials are ‘weapons’, and experts (researchers, medical personnel) are the ‘fighters’, leaving aside people’s experiences and social realities. In contrast, the ‘body in balance’ metaphor, linked to the ‘hot and cold’ theory, as used in Iquitos and many other parts of the world, is clearly person-centred. Like the disease, medicines affect each person differently, according to their age and sex, to what they eat and drink, to their work and other activities. Anti-malarial drugs can heal, but they can can produce or increase imbalance and, therefore, disease. In this sense, the local model of malaria and its treatment in Iquitos is closer to patient/people-centred approaches than anti-malarial campaigns. A patient-centred approach includes not only the use of efficacious and quality medicinal products to target the disease, but takes a person’s circumstances, life conditions and feelings into account [
26].
The shift from pathogen to patient-centred approaches has implications for health promotion because a focus on people necessarily requires a horizontal, participatory approach that goes beyond designing health messages to encourage people to accept and adhere to treatments in order to ‘fight a disease’. Formative research is a useful way to elaborate health promotion strategies together with the communities, and as such respond to real needs [
27‐
29]. With regard to adherence promotion in the Peruvian context, a formative research approach would consider, for example, the interconnected nutritional, recreational, climatic, work conditions and so on, and identify, together with the affected communities, the best ways to commensurate effective treatments with local perceptions and experiences.
Moreover, the ‘hot and cold’ theory can serve as a valuable entry point for a systemic response to the disease accounting for its social and ecological determinants. Being multicausal and systemic, dynamic and relational, this perspective opens a window of opportunity for a multisectorial and transdisciplinary approach uniting public health goals and community needs.