A Screening Instrument to Measure the Prevalence of Neurological Disability in Resource-Poor Settings

Abstract

Background: Very little is known about the prevalence of neurological morbidity in Africa. Much of this is due to the difficulty in performing epidemiological surveys in these settings. A screening instrument to measure neurological disease in resource-poor settings was designed by the World Health Organization in 1981, but several problems with it have subsequently been recognized. Methods: We created a new screening instrument that addressed problems with the original instrument identified by prior investigators, and that included questions to identify diseases of public health significance and broad neurological syndromes. This new instrument was tested in an outpatient setting in Moshi, Tanzania. We compared the sensitivity and specificity of the new instrument to the original 1981 WHO instrument. Results: We tested the survey on 128 participants. Of these, 63 had neurological diagnoses, 21 had pain-only diagnoses and 44 had no neurological diagnoses. The survey was well received by all the participants. A nonmedical interviewer was trained to administer and interpret a simple neurological examination without difficulty. The median time to administer the instrument was 13 min (interquartile range 10–17 min). The sensitivity of the new instrument improved that of the WHO instrument from 98.4 to 100%, but the difference was not statistically significant (p = 0.44). However, the specificity significantly improved from 29.2 to 61.0% (p = 0.001). Conclusions: We have developed a screening instrument to measure the prevalence of neurological morbidity in resource-poor settings. It was shown to be highly feasible, highly sensitive, and more specific than the existing WHO instrument.

A Novel 6-Item Screening Questionnaire for Parkinsonism: Validation and Comparison Between Different Instruments

“…This newly developed instrument had a Youden's index of 0.861 and specificity of 96%, which was higher than all other questionnaires; while, the WHO-recommended questionnaires [5,14] showed a higher sensitivity (95%) at a cost of lower specificity (60 and 72%). Our instrument also showed the highest ROC-AUC (0.977) compared to other instruments such as the SNES [4] (0.934), WHOmodified instrument [14] (0.933), and recommended index by Duarte et al [16] (0.947), Setthawatcharawanich et al [18] (0.950) and Chan et al [17] (0.968) to screen Parkinsonism. It is worth noting that all of these instruments were implemented and assessed on the same original database in which our newly screening questionnaire was developed from.…”

“…The content validity of different items in our instrument was also acceptable ranging from 0.74 to 0.81, while Setthawatcharawanich et al [18] showed a wider range (0.6-1.0) for their 4-item screening questionnaire. The number of selected items in our questionnaire (n = 6) is lower than some previously developed instruments such as the BHSQ [13] with 16 questions, the ones developed by Tanner et al [15] , Duarte et al [16] , and Sevillano et al [19] with 9 items and the WHO-modified tool [14] with 7 items. However, our instrument showed better diagnostic values, reliability and content validity.…”

“…Finally, the best question for each of the symptoms or signs was selected. As a result, a comprehensive screening questionnaire was developed; it was actually constructed by combining the items from previously validated questionnaires used for screening PD including the screening instrument of the Sicilian neuro-epidemiology study (SNES) [4] , the Baylor Health Screening Questionnaire (BHSQ) [13] , telephone questionnaire for Parkinson's disease [6] , WHO screening instrument to measure the prevalence of neurological disability in resource-poor settings [5,14] , and the questionnaires either developed or modified by Tanner [15] , Duarte [16] , Chan [17] , Setthawatcharawanich [18], and Sevillano [19] . Each of these screening questionnaires was designed based on symptoms suggestive of Parkinson's disease except for the SNES and WHO tools, which also contain several questions on other neurological symptoms as well.…”

“…All screening questions were merged and redundant items that questioned the same symptom from different questionnaires were excluded. Based on the objective of our study, items that required physical examination (from the SNES [4] and WHO [5,14] tools) by a clinician were not included in the merged questionnaire. On the other hand, some general questions on non-PD-specific neurologic symptoms from the SNES questionnaire [4] were kept in the merged instrument to check the validity of the answers from the patients.…”

Epidemiology in a Globalising World: New Challenges for Researchers

“…The World Health Organisation has developed the STEPS programme for surveillance of stroke and vascular risk factors in lowand middle-income countries [6] , and in a recent issue of Neuroepidemiology, a screening instrument to measure the prevalence of neurological disability in resource-poor settings was presented [7] .…”