Disability after Encephalitis: Development and Validation of a New Outcome score/Invalidite Post-Encephalitique : Conception et Validation D'une Nouvelle Echelle d'evaluation/Incapacidad Tras la Encefalitis: Desarrollo Y Validacion De Una Nueva Escala De Resultados

Introduction Neurological disability is a major problem among children in resource-poor countries but the true burden of disability is unknown because there is no simple and reliable way of measuring it. (1) The ability to measure disease burden is especially important for Japanese encephalitis, which is a major cause of death and disability in Asia. The disease is caused by the mosquito-borne flavivirus, Japanese encephalitis virus, and is spreading. Recently, there have been large outbreaks in India and Nepal and it is estimated that there are 20 000 to 175 000 cases globally each year. (2-5) Although vaccines against Japanese encephalitis have been available for many years, they have not been widely used, partly because policy-makers lack information about disease burden. (4,6,7) Moreover, the proportion of patients reported to have severe sequelae after infection varies widely, from 19 to 71%. (8-11) A major reason for this uncertainty is the lack of a standard method for assessing the outcome of Japanese encephalitis and other forms of acquired brain injury among children in resource-poor countries. Even in industrialized countries, tools for assessing disability in children are not as well developed as for adults. (12) The gold-standard method requires a large multidisciplinary team and involves multiple lengthy assessments over an extended period of time. Although some tools have recently been redeveloped for use in resource-poor settings, they often still require lengthy assessments by trained personnel. (13,14) We set out to develop a simple score for assessing disability in children affected by Japanese encephalitis that can be applied by health-care workers with minimal training. We focused on whether the disability was likely to make a child dependent on others, because this is the key issue in terms of disease burden, as well as the single most important parameter for the children themselves. The score we developed, which has become known as the Liverpool Outcome Score, (15) was field-tested at two sites in south-eastern Asia: Bellary in India and Sibu in Malaysia. It is also now being used in Bangladesh, Cambodia, Indonesia, (16,17) the Lao People's Democratic Republic and Viet Nam (S Hills, et al. unpublished data, 2008). Methods Setting The new post-encephalitis disability assessment score was developed, piloted and tested in two different clinical settings representative of locations across Asia where Japanese encephalitis occurs: (i) the Vijayanagar Institute of Medical Sciences, which is a government hospital in Bellary in southern India with basic diagnostic facilities but no paediatric intensive care facilities that serves the city (population: 0.5 million) and district (population: > 2 million) of Bellary; (18) and (ii) Sibu Hospital, which is a referral hospital in Sarawak, Malaysia, with full intensive care facilities that serves the town of Sibu (population: 250 000) and the central region of Sarawak (population: 650 000). (19) [FIGURE 1 OMITTED] The outcome score A pilot version of the outcome score based on 20 questions was developed after a literature review and the examination of assessment tools used in developed and resource-poor countries, including the Ten Questions screening questionnaire for childhood disability, the Denver II child development screening test, the Paediatric Evaluation of Disability Inventory (PEDI) and three other assessment tools (Fig. 1). (20-23) Written informed consent was obtained from the parent or guardian of each child. Approval for the study was granted by the ethics committees of the University of Liverpool in the United Kingdom of Great Britain and Northern Ireland and the Vijayanagar Institute of Medical Sciences in India, and the director of health of the state of Sarawak and the hospital director of Sibu Hospital in Sarawak. Participants After a pilot study in 2006 involving 51 children in India, the score questionnaire was revised and applied in its current 15-question format in 2006 to a cohort of children who had had Japanese encephalitis in Sibu, Malaysia, (11) and to controls. …