Undernutrition and the incidence of tuberculosis in India: National and subnational estimates of the population-attributable fraction related to undernutrition.

Background. India has the largest global burden of tuberculosis (TB)-related morbidity and mortality as well as undernutrition. Undernutrition impairs cell-mediated immunity, is a risk factor for the development of TB, and has the largest potential impact on the incidence of TB in countries with a high burden of TB. Methods. We refined the national estimate of the population-attributable fraction (PAF) for undernutrition in India to report the first subnational estimates, and stratified these further for age, gender, residence, caste and socioeconomic status. We also compared the PAF related to undernutrition in India with that in 15 other countries with a high burden of TB. We used data on body mass index (BMI) from the National Family Health Survey-3 (NFHS-3), as well as risk estimates for a low BMI from a recently published population-based study which had controlled for several confounders. Results. The overall prevalence of undernutrition in the age group of 15–49 years was 35.6% among women and 34.2% among men. About half (55.4%; 95% CI 27.4– 75.9) of all cases of active TB among women and 54.4% (95% CI 26.5–75.2) of all cases among men were attributable to undernutrition. In the age group of 15–19 years, the PAFs for undernutrition were 62% and 67% among women and men, respectively. The PAF of undernutrition was higher in rural areas, in scheduled castes, scheduled tribes and other backward classes, and in the lower quintiles of the wealth index. The PAF of undernutrition exceeded 50% in most states, and the largest PAFs were seen among women of scheduled tribes in central India. Among countries with a high burden of TB, India had the highest PAF related to undernutrition. Conclusion. Addressing the problem of endemic undernutrition among adolescents and adults in India could complement the current TB control strategy based on case management, and help reduce the incidence of TB in India in line with global targets.

Serological tests for the diagnosis of active tuberculosis: relevance for India.

Diagnostic tests for active tuberculosis (TB) based on the detection of antibodies (serological tests) have been commercially available for decades, although no international guidelines have recommended their use. An estimated 1.5 million serological TB tests, mainly enzyme-linked immunosorbent assays, are performed in India alone every year, mostly in the private sector. The cost of serological tests in India is conservatively estimated at US $15 million (825 million) per year. Findings from systematic reviews on the diagnostic accuracy of serological tests for both pulmonary and extra-pulmonary TB suggest that these tests are inaccurate and imprecise. A cost-effectiveness modelling study suggests that, if used as a replacement test for sputum microscopy, serology would increase costs to the Indian TB control sector approximately 4-fold and result in fewer disability-adjusted life years averted and more false-positive diagnoses. After considering all available evidence, the World Health Organization issued a strong recommendation against the use of currently available commercial serological tests for the diagnosis of TB disease. The expanding evidence base continues to demonstrate that the harms/risks of serological tests far outweigh the benefits. Greater engagement of the private sector is needed to discontinue the use of serological tests and to replace these tests with WHO-endorsed new diagnostics in India. The recent ban on import or sale of TB serological tests by the Indian health ministry is a welcome step in the right direction.

Accuracy and reliability of palpation and percussion for detecting hepatomegaly: a rural hospital-based study.

BACKGROUND: Palpation and percussion are standard bedside techniques used to diagnose hepatomegaly. Ultrasonography is a noninvasive and accurate method for measurement of liver size, but many patients in developing countries have limited access to it. We compared the accuracy of palpation and percussion in a rural population in central India, using ultrasonography as a reference standard. METHODS: The study design was a blinded, cross-sectional analysis of a hospital-based case series. Three physicians, blind to clinical data and to each other's results, independently used palpation and percussion to detect hepatomegaly. Diagnostic accuracy was measured by computing sensitivity, specificity, and likelihood ratio values. Inter-physician agreement was assessed using the kappa statistic. RESULTS: Of the 180 study patients, 36 (20%) had enlarged liver on ultrasonography. The likelihood ratios for findings at both palpation (2.2, 3.0, and 2.5 for the three physicians, respectively) and percussion (1.1 for all three physicians) as predictors of true hepatomegaly were low. The kappa values for inter-observer agreement between three physicians for the presence of hepatomegaly at palpation (=0.44-0.53) and percussion (=0.17-0.33) were low, indicating poor reliability of these techniques. CONCLUSION: Clinical assessment of hepatomegaly by palpation and percussion lacks both accuracy and reliability.

Risk factors for acute myocardial infarction in a rural population of central India: a hospital-based case-control study.

BACKGROUND: There is a paucity of data on the relative importance of various traditional risk factors for coronary artery disease among rural Indians. We conducted a prospective case-control study to determine the risk factors for acute myocardial infarction in a rural population of central India. METHODS: We recruited 111 consecutive patients admitted to our hospital with a first episode of acute myocardial infarction and 222 age- and sex-matched controls. Demographics, anthropometric measures, lipids, blood glucose, smoking and other lifestyle factors were compared among cases and controls. Multivariate analyses were used to identify the risk factors independently associated with acute myocardial infarction. RESULTS: Elevated fasting blood glucose (odds ratio [OR] 8.9; 95% confidence interval [CI] 4.5, 17.9), abnormal waist-hip ratio (OR 3.0; 95% CI 1.7, 5.4) and income (OR 4.0 and 5.9 for the high- and middle-income categories, compared to the lowest category) were independently associated with the first episode of acute myocardial infarction. Abnormal triglycerides (OR 1.7; 95% CI 0.9, 3.1) and current smoking (OR 1.9; 95% CI 0.9, 4.0) were risk factors but were not statistically significant. CONCLUSION: Reduction in blood glucose levels and truncal obesity may be important in controlling the burden of coronary artery disease in rural Indians.

Systematic reviews and meta-analyses: an illustrated, step-by-step guide.

Systematic reviews and meta-analyses synthesize data from existing primary research, and well-conducted reviews offer clinicians a practical solution to the problem of staying current in their fields of interest. A whole generation of secondary journals, pre-appraised evidence libraries and periodically updated electronic texts are now available to clinicians. However, not all systematic reviews are of high quality, and it is important to be able to critically assess their validity and applicability. This article is an illustrated guide for conducting systematic reviews. A clear understanding of the process will provide clinicians with the tools to judiciously appraise reviews and interpret them. We hope that it will enable clinicians to conduct systematic reviews, generate high-quality evidence, and contribute to the evidence-based medicine movement.

Poor accuracy of the Siriraj and Guy's hospital stroke scores in distinguishing haemorrhagic from ischaemic stroke in a rural, tertiary care hospital.

BACKGROUND: In India stroke is associated with a high morbidity and mortality. Bedside clinical examination does not always help in distinguishing cerebral infarction from intracranial haemorrhage. We evaluated the accuracy of the Guy's hospital and Siriraj stroke scores in distinguishing haemorrhagic from ischaemic stroke in a rural setting. METHODS: Patients with suspected stroke admitted to a rural teaching hospital were prospectively enrolled. Two investigators collected data for computing the Guy's hospital and Siriraj scores. Cut-off points, as described by the authors of the original scores, were used to predict haemorrhage and infarction. The scores were compared in a blind and independent manner with the computed tomography (CT) scan. The sensitivity, specificity, positive and negative likelihood ratios and agreement between the two scores were calculated. RESULTS: Of the 259 patients admitted for suspected stroke, 134 patients (73 men) underwent both clinical evaluation and a CT scan. The Siriraj score discriminated haemorrhage from infarction with a sensitivity of 78.5% (95% CI: 66.5, 87.7) and specificity of 71% (95% CI: 52, 85.8). The likelihood ratio of a positive test was 2.7 (95% CI: 1.54, 4.75) and that of a negative test was 0.3 (95% CI: 0.17, 0.53). For the Guy's hospital score the sensitivity was 81% (95% CI: 68.6, 90.1), specificity 76.2% (95% CI: 52.8, 91.8), likelihood ratio of a positive test 3.4 (95% CI: 1.57, 7.39) and that of a negative test 0.25 (95% CI: 0.11, 0.54). Both scores, when combined, were 80% sensitive (95% CI: 66.3, 90) and 80% specific (95% CI: 51.9, 95.7). The agreement between the two scores was modest (kappa = 0.51), but very good (kappa = 0.93) after exclusion of equivocal score results. CONCLUSION: Our study suggests that neither of the stroke scores is sufficiently accurate for distinguishing the type of stroke. CT scan, and not history and clinical signs, can accurately identify haemorrhage from infarction in acute stroke.