Explanatory models of illness and pluralistic care

The explanatory-model gap is the distance between the model the clinician holds and the model the patient holds for the same episode of sickness. It exists because the biomedical account is itself an explanatory model, not the absence of one: it makes strong claims about aetiology (a pathogen, a lesion, a gene), about pathophysiology (a mechanism inside the body) and about treatment (a drug or a procedure), and it silences rival claims without arguing with them. Leon Eisenberg separated disease from illness in 1977, and Kleinman turned the distinction into a clinical tool: the clinician is trained to see the first, the patient lives the second, and neither is an error. The gap becomes dangerous when nobody examines it. The clinician reads the patient’s behaviour through her own model and concludes that he is ignorant, stubborn or non-compliant; the patient reads the clinician through his model and concludes that the medicine is weak, dangerous or incomplete. James Trostle argued in 1988 that “compliance” functions as an ideology: it takes medical authority to be correct by definition and locates every failure in the patient, so the gap is never measured and never closed. The consequences are visible in any outpatient record — medication stopped without anyone being told, a second and third healer consulted in secret, re-presentation only when the illness is advanced. The nursing correction is to treat the gap as a clinical variable, like blood pressure: something assessed at every consultation, recorded, and acted upon. Two questions do most of the work — what does the patient believe is happening, and what does he expect this treatment to do?

Kleinman proposed in 1978 that a health care system is best understood as a local cultural system with three sectors, not as a single ladder of progress towards hospital medicine. The popular sector is the largest: it is where symptoms are first named, where most treatment is given, and where the decision to consult anyone else is taken. It keeps almost no records and employs no staff, which is why planners consistently underestimate it and why a service can be technically available yet hardly used. The folk sector contains non-professional specialists, both sacred (diviners, religious healers) and secular (herbalists, bone setters, traditional birth attendants). The professional sector contains the organised, legally recognised practitioners: medicine, nursing, pharmacy, and in some countries codified traditional systems such as Ayurveda or Chinese medicine. Movement between the three is neither random nor a sign of confusion. Lola Romanucci-Ross described a hierarchy of resort in 1969: people begin with the cheapest and most familiar option and move outward as it fails, though the sequence is a tendency rather than a fixed staircase, and a frightening symptom can send a family straight to the hospital. John Janzen, working among the BaKongo in Lower Zaire in 1978, added the decisive social fact: therapy is managed by a group of kin who investigate, finance, evaluate and authorise each step, so the person who decides may never enter the consulting room. He called the recurring dispute over who has authority to choose the therapy management problem. A nurse who negotiates only with the patient, and not with the therapy management group, often finds that an agreed plan is reversed at home within a day. Policy has moved in the same direction as the anthropology: the WHO traditional medicine strategy 2014–2023 asks Member States to regulate and integrate traditional and complementary practitioners and products into national health systems, rather than treating them as a survival of the past.

Negotiation is a routine, not a favour granted to a difficult patient. Kleinman’s recommendation is to negotiate over the five aspects of the model separately, because agreement is not needed everywhere: a nurse may fail to convince a family about aetiology and still secure the full course of treatment by agreeing about the course of the illness and the danger signs. A workable sequence has three moves. Elicit first, with the five questions, in the patient’s language and without signalling the answer you want. Explain second, in the patient’s vocabulary rather than in yours: “this medicine kills the small animals in the blood” travels further than “artemisinin-based combination therapy”, and “the salt water replaces what the diarrhoea takes out” travels further than “oral rehydration salts”. Negotiate third, separating what is merely unfamiliar from what is unsafe. A harmless herbal tea taken alongside antimalarials can be tolerated and recorded; a prayer that replaces antiretrovirals, or heat applied to a fresh fracture, cannot. The language of practice has moved the same way: concordance, promoted in British pharmacy from 1997, replaced compliance and adherence in order to describe a consultation between equals rather than a patient obeying instructions. Two techniques make the negotiation concrete. Teach-back — asking the patient to explain the plan in his own words — exposes the misunderstanding that a polite nod conceals. A danger-signs contract — “if he cannot drink, vomits everything, or convulses, he comes back at once” — gives the family a rule that works inside their own model, because it is about what they will see, not about what the nurse knows. Finally, record the model in the file. Without that sentence the next shift, or the next healer, reopens a question that was already settled.