Validation of a stroke symptom questionnaire for epidemiological surveys

Abstract

CONTEXT AND OBJECTIVE: Stroke is a relevant issue within public health and requires epidemiological surveillance tools. The aim here was to validate a questionnaire for evaluating individuals with stroke symptoms in the Stroke Morbidity and Mortality Study (Estudo de Mortalidade e Morbidade do Acidente Vascular Cerebral, EMMA), São Paulo, Brazil. DESIGN AND SETTING:This was a cross-sectional study performed among a sample of the inhabitants of Butantã, an area in the western zone of the city of São Paulo. METHODS:For all households in the coverage area of a primary healthcare unit, household members over the age of 35 years answered a stroke symptom questionnaire addressing limb weakness, facial weakness, speech problems, sensory disorders and impaired vision. Thirty-six participants were randomly selected for a complete neurological examination (gold standard). RESULTS:Considering all the questions in the questionnaire, the sensitivity was 72.2%, specificity was 94.4%, positive predictive value was 92.9% and negative predictive value was 77.3%. The positive likelihood ratio was 12.9, the negative likelihood ratio was 0.29 and the kappa coefficient was 0.67. Limb weakness was the most sensitive symptom, and speech problems were the most specific. CONCLUSIONS:The stroke symptom questionnaire is a useful tool and can be applied by trained interviewers with the aim of identifying communitydwelling stroke patients, through the structure of the Family Health Program. TIPO DE ESTUDO E LOCAL:Estudo transversal realizado em uma amostra de habitantes do Butantã, uma área na zona oeste da cidade de São Paulo. MÉTODOS:Em todos os domicílios de área adstrita de uma unidade básica de saúde, moradores com mais de 35 anos responderam questionário de sintomas de acidente vascular cerebral enfocando fraqueza de membros e facial, dificuldade em falar, alteração de sensibilidade e déficit de visão.Foram selecionadas 36 participantes aleatoriamente para exame completo com neurologista (padrão-ouro).RESULTADOS: Considerando todas as questões do questionário, a sensibilidade foi de 72,2%, a especificidade, 94,4% e os valores preditivos foram 92,9% (positivo) e 77,3% (negativo). As razões de verossimilhança foram 12,9 (positiva) e 0,29 (negativa) e o coeficiente kappa obtido foi 0,67.Fraqueza de membros foi o sintoma mais sensível e dificuldade para falar, o mais específico.CONCLUSÃO: O questionário de sintomas cerebrovasculares é um instrumento útil, e pode ser aplicado por entrevistadores treinados com intuito de identificar pacientes que sofreram evento cerebrovascular na comunidade através da estrutura do Programa Saúde da Família.

"EMMA Study: a Brazilian community-based cohort study of stroke mortality and morbidity"

“…A total of 577 subjects answered the final questionnaire, of whom 243 were screened positive for stroke, based on a questionnaire, and were validated by a board-certified neurologist. 23,24 The age-adjusted prevalence rate for men was 4.6% (95% CI: 3.5-5.7). For women, the prevalence rate was 6.5% (95% CI: 5.5-7.5) and, when considering only one question, the rate was 4.8% (95% CI: 3.9-5.7).…”

Prevalence of stroke and associated disability in Brazil: National Health Survey - 2013

“…In the studies held in São Paulo and Amazonas were used two strategies for the diagnosis of stroke: the first one used a self-reported similar question used in the PNS and the second used a brief questionnaire composed by six questions about stroke symptoms validated by a neurologist in a previous study 15 . The prevalence of most positive answers among women was associated with use of stroke symptoms questionnaire.…”

Prevalence and risk factors for stroke in a population of Southern Brazil

“…More recently, Abe et al 21 conducted the study called EMMA (Portuguese acronym for Mortality and Morbidity of Cerebrovascular Accident Study), to validate a questionnaire for stroke screening in a vulnerable community of São Paulo city, Brazil. The EMMA questionnaire 21 consisted of six questions, one about previous diagnosis of stroke confirmed by a physician and five about symptoms (including visual deficit).…”

“…The EMMA questionnaire 21 consisted of six questions, one about previous diagnosis of stroke confirmed by a physician and five about symptoms (including visual deficit). Individuals from 35 years were included; the cases were considered positive when there were affirmative answer to two or more questions, if the previous diagnosis of stroke was included or to three of any questions, with confirmation by physician or not.…”

“…The etiology of symptoms, such as hemiplegia or hemiparesis, in adult patients is limited to stroke and head trauma in most communities 20 . The questionnaires possibly underestimate milder cases, but can identify cases with the highest degree of physical disability and require more resources for rehabilitation 21 .…”