Cognitive predictors of adherence to malaria prophylaxis regimens on return from a malarious region: a prospective study

Cases of 'imported malaria' into countries where malaria is not endemic ape increasing and evidence suggests that non-use of malaria prophylaxis and l ack of adherence are contributing to this increase. Non-adherence may be es pecially likely because chemoprophylaxis regimens require travellers to con tinue to take medication for 4 weeks after their return from a malarious re gion. This study investigated the extent to which cognition measures specif ied by the theory of planned behaviour and the health belief model could di stinguish between those who reported greater or lesser adherence after thei r return. Cognitions were measured using a brief questionnaire on the day o f departure from the malarious region and reports of adherence were collect ed between 5 and 7 weeks later. Data from two longitudinal samples of UK to urists returning from The Gambia were analysed; 106 mefloquine users and 61 chloroquine and proguanil users. Results suggested that malaria prophylaxi s adherence could be improved. 22.5% of mefloquine users and 31% of chloroq uine and proguanil users reported adherence for 3 weeks or less. A model ba sed on the theory of planned behaviour explained approximately 50% of the v ariance in reported adherence amongst mefloquine users and 40% amongst chlo roquine and proguanil users, comparing favorably with other published appli cations of the theory. Findings suggest that targeting key cognitions could enhance adherence on return from malarious regions. Enhancing perceived co ntrol over adherence may be important as well as emphasising susceptibility to malaria infection. Reassuring mefloquine users concerning potential sid e effects of the drug may also encourage adherence on return. Implications for future research are discussed, (C) 1999 Elsevier Science Ltd. All right s reserved.