Seasonal variability in size-resolved hygroscopicity of sub-micron aerosols over the Western Ghats, India: Closure and parameterization.

Hygroscopicity of atmospheric aerosol primarily depends on the size and chemical composition of the particle and is important for estimating anthropogenic aerosol radiative forcing. There is limited information exists over the Indian region on size segregated aerosol hygroscopicity (κ) in different seasons. This study presents 'κ' as derived from a Humidified Tandem Differential Mobility Analyzer (HTDMA) over a High Altitude Cloud Physics Laboratory (HACPL) in the Western Ghats, India for more than a year (from May 2019 to May 2020). The average hygroscopicity values of aerosol particles of diameters 32, 50, 75, 110, 150, 210 and 260 nm at 90 % RH condition are 0.19, 0.18, 0.16, 0.17, 0.18, 0.20, 0.21 respectively during the entire observation period. κ was observed to decrease with an increase in size in the Aitken mode regime (32-75 nm) and an increase in the accumulation mode (110-260 nm). Seasonal variation of hygroscopicity for a wide range of particle diameters is reported which is highly demanding as there is a change in the air mass flow pattern in each of the seasons. The diurnal cycle of hygroscopicity showed a prominent peak during the midnight to early morning hours followed by a decrease in the forenoon hours and a secondary peak in the afternoon hours. κ is found to be higher in pre-monsoon compared to winter season as Chl is approximately 3 % higher in pre-monsoon and NH4Cl is highly hygroscopic among the assumed chemical composition. Hygroscopicity derived through chemical speciation observations assuming internal and external mixing of aerosols i.e. κinter and κexter are overestimating as compared to κHTDMA. However, the bias between kexter and kHTDMA is relatively lower as external mixing type of aerosol is evident through the growth factor data sets measured by HTDMA. Utilizing the hygroscopicity measurements available for discrete diameters by HTDMA, a parameterization of hygroscopicity with the dry diameter of sub-micron particles is developed.

Closed-loop optogenetic control of the dynamics of neural activity in non-human primates.

Electrical neurostimulation is effective in the treatment of neurological disorders, but associated recording artefacts generally limit its applications to open-loop stimuli. Real-time and continuous closed-loop control of brain activity can, however, be achieved by pairing concurrent electrical recordings and optogenetics. Here we show that closed-loop optogenetic stimulation with excitatory opsins enables the precise manipulation of neural dynamics in brain slices from transgenic mice and in anaesthetized non-human primates. The approach generates oscillations in quiescent tissue, enhances or suppresses endogenous patterns in active tissue and modulates seizure-like bursts elicited by the convulsant 4-aminopyridine. A nonlinear model of the phase-dependent effects of optical stimulation reproduced the modulation of cycles of local-field potentials associated with seizure oscillations, as evidenced by the systematic changes in the variability and entropy of the phase-space trajectories of seizures, which correlated with changes in their duration and intensity. We also show that closed-loop optogenetic neurostimulation could be delivered using intracortical optrodes incorporating light-emitting diodes. Closed-loop optogenetic approaches may be translatable to therapeutic applications in humans.

Assessment of prescribing pattern of drugs and completeness of prescriptions as per the World Health Organization prescribing indicators in various Indian tertiary care centers: A multicentric study by Rational Use of Medicines Centers-Indian Council of Medical Research network under National Virtual Centre Clinical Pharmacology activity.

OBJECTIVE: The rational use of medicines as per the World Health Organization (WHO) should be practiced globally. However, data regarding the completeness of the prescriptions and their rational use is lacking from developing countries like India. Thus, the aim of this study was to assess the prescribing patterns of drugs and completeness of prescriptions as per WHO core drug use and complementary indicators to provide real-life examples for the Indian Council of Medical Research (ICMR) online prescribing skill course for medical graduates. METHODS: Prescriptions of the patients, fulfilling inclusion criteria, attending Outpatient Departments of various specialties of tertiary care hospitals, were collected by thirteen ICMR Rational use of medicines centers located in tertiary care hospitals, throughout India. Prescriptions were evaluated for rational use of medicines according to the WHO guidelines and for appropriateness as per standard treatment guidelines using a common protocol approved by local Ethics committees. RESULTS: Among 4838 prescriptions, an average of about three drugs (3.34) was prescribed to the patients per prescription. Polypharmacy was noted in 83.05% of prescriptions. Generic drugs were prescribed in 47.58% of the prescriptions. Further, antimicrobials were prescribed in 17.63% of the prescriptions and only 4.98% of prescriptions were with injectables. During the prescription evaluation, 38.65% of the prescriptions were incomplete due to multiple omissions such as dose, duration, and formulation. CONCLUSION: Most of the parameters in the present study were out of the range of WHO-recommended prescribing indicators. Therefore, effective intervention program, like training, for the promotion of rational drug use practice was recommended to improve the prescribing pattern of drugs and the quality of prescriptions all over the country.

Epidemiological investigation of viral hepatitis E outbreak in two colocated training centers.

Background: A high number of jaundice cases were reported from two colocated training centers in North India. This outbreak was investigated to describe the epidemiology, identify risk factors, and recommend preventive and control measures. Methods: Initial line list was prepared, and case definition was defined as "the presence of icterus or passage of yellow-colored urine with fever/anorexia/vomiting/abdominal pain in a resident of Military Station A between 03/04/2016 to 06/06/2016". Case search was conducted through surveillance. An unmatched 1:1 case-control study was conducted to evaluate the associated risk factors. All cases were tested for hepatitis markers. Environmental investigation of food and water sources was conducted to identify the source of infection. Results: Of 172 cases, all were males from two co-located military training centers (attack rate, 4.7%). Clinical features included icterus (100%), yellowish discoloration of urine (98.9%), anorexia (97.22%), fever (80%), nausea/vomiting (56%), and abdominal pain (52.77%). Only one case (0.6%) had complication of fulminant hepatitis, and there were no deaths (CFR = 0%). Consumption of juice with ice from juice shops was significantly associated with illness (Odds Ratio-14.3 [95%CI 7.4-27.6]). Of 172 cases, 167 (97.1%) tested anti-HEV-IgM positive. Juice shops in training centers were using ice made from contaminated water with positive coliform test. All other water samples tested satisfactory. No cross-contamination of water pipelines with sewage was observed. Conclusion: Epidemiological evidence concludes that a large viral hepatitis E outbreak was likely caused by consumption of juice with contaminated ice. Early stoppage of contaminated ice usage led to timely control of the outbreak.

Chlorogenic Acid Enriched Green Coffee Ameliorated Renal Injury in Rats.

The incidence of acute kidney injury (AKI) during the treatment with gentamicin (GM) is very common in hospitalized patients. Green coffee bean, containing chlorogenic acid (CGA) has been reported to improve non communicable diseases. In the present study, CGA enriched fraction of green coffee bean was evaluated on GM induced nephrotoxicity in rats. It was a preclinical case-controlled experimental intervention conducted in the Department of Pharmacology, R G Kar Medical College, Kolkata, India from 2016-2019 using animal model. CGA content of green coffee bean extract (GCBE) was isolated and quantified by high performance thin layer chromatography (HPTLC) (6.426%). The rats were treated with GCBE at the dose of 100, 200 and 400mg/kg in gentamicin (GM) induced AKI for five consecutive days. At day 6, the renal function was assessed through analysing urine, blood and renal tissues. GCBE dose dependently and significantly (p<0.001) lowered blood urea, creatinine and potassium while, enhanced sodium compared to AKI control. Moreover, it showed significant elevation in glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) and reduction in lipid peroxides (p<0.001). It was suggested that chlorogenic acid of green coffee seed can protect kidney through down regulation of p53 transcription factor and thereby attenuation of oxidative stress, inflammation and apoptotic process in renal tubules.

Conversion of clinically isolated syndrome to multiple sclerosis: a prospective multi-center study in Eastern India.

BACKGROUND: In White populations more than 60% of clinically isolated syndrome (CIS) convert to multiple sclerosis (MS) on a long-term follow-up; several predictors for conversion have been identified. OBJECTIVE: This study aimed to determine the conversion rate and the predictors of conversion from CIS to MS (McDonald 2010) among Indians. The other objective was to evaluate the diagnostic accuracy of the new McDonald 2017 criteria in prediction of a second clinical attack. METHODS: Clinical and demographic data of CIS cohorts were collected. Baseline investigations included cerebrospinal magnetic resonance imaging (MRI) with contrast and cerebrospinal fluid (CSF) testing for oligoclonal band (OCB). Follow-up clinical and MRI examinations were performed annually for at least 24 months. RESULTS: Of the 82 subjects (age range 15-58 years), 36 (43.9%) converted to MS; 31/82 (37.8%) converted in 24 months. The predictors for conversion were earlier age of onset, CSF-OCB, cerebral MRI T2 lesion count, and periventricular and juxtacortical location of lesions. Twenty-two (26.83%) CIS fulfilled the McDonald MS 2017 criteria at baseline. CONCLUSION: In this first prospective study of CIS in India, the risk factors for conversion are similar but the conversion rate to MS is lower than that in the western nations.

Cost and cost-effectiveness of health behavior change interventions implemented with self-help groups in Bihar, India.

INTRODUCTION: Health interventions implemented with self-help groups (SHGs) enhance the relevance and acceptability of the health services. The Parivartan program was implemented in eight districts of Bihar with women's self-help groups to increase adoption of maternal and newborn health behaviors through layering health behavior change communication. This study estimates the cost and cost-effectiveness of a health behavior change program with SHGs in Bihar. METHODS: Cost analysis was conducted from a provider's perspective. All costs have been presented in US dollars for the purpose of international comparisons and converted to constant values. The effectiveness estimate was based on the reported changes in select newborn care practices. A decision model approach was used to estimate the potential number of neonatal deaths averted based on adoption of key newborn care practices. Using India's life expectancy of 65 years, cost per life year saved was calculated. A one-way sensitivity analysis was conducted using the upper and lower estimates for various variables in the model, and functionality of SHGs. RESULTS: The cost of forming an SHG group was US$254 and that of reaching a woman within the group was US$19. The unit cost for delivering health interventions through the Parivartan program was US$148 per group and US$11 per woman reached. During an 18 months period, Parivartan program reached around 17,120 SHGs and an estimated 20,544 pregnant women resulting in an estimated prevention of 23 neonatal deaths at a cost of US$3,825 per life year saved. CONCLUSION: SHGs can be an effective platform to increase uptake of women's health interventions and follow-up care, and also to broaden their utility beyond microfinance, particularly when they operate at a larger scale.

Medication Adherence in Kidney Transplant Recipients in an Urban Indian Setting.

Medication nonadherence is a known problem after renal transplantation and can vary from one setting to another. Since it can lead to negative outcomes, it is important to develop intervention strategies to enhance adherence in a given setting using determinants identified through exploratory studies. We explored nonadherence in renal transplant recipients. A longitudinal survey was done with adult renal transplant recipients at a tertiary care public and two private hospitals of Kolkata. Subjects were followed-up for 1 year. After screening for medication adherence status by the four-item Morisky Medication Adherence Scale, those admitting to potential nonadherence were probed further. A patient was deemed to be nonadherent if failing to take medicines on appointed time (doses missed or delayed by more than 2 h) more than three times in any month during the observation period. A pretested questionnaire was used to explore potential determinants of nonadherence. Data of 153 patients recruited over a 2-year were analyzed. The extent of nonadherence with immunosuppressant regimens was about 31% overall; 44% in the public sector and 19% in the private sector (P < 0.001). Nonadherence with other medication was around 19% in both the sectors. Several potential demographic, socioeconomic and psychosocial determinants of nonadherence were identified on univariate analysis. However, logistic regression analysis singled out only the economic status. This study had updated the issue of nonadherence in renal transplant recipients in the Indian setting. Strategies to improve medication adherence can be planned by relevant stakeholders on the basis of these findings.

Stoichiometry, Length, and Wall Thickness Optimization of TiO2 Nanotube Array for Efficient Alcohol Sensing.

The present study concerns development of an efficient alcohol sensor by controlling the stoichiometry, length, and wall thickness of electrochemically grown TiO2 nanotube array for its use as the sensing layer. Judicious variation of H2O content (0, 2, 10 and 100% by volume) in the mixed electrolyte comprising ethylene glycol and NH4F resulted into the desired variation of stoichiometry. The sensor study was performed within the temperature range of 27 to 250 °C for detecting the alcohols in the concentration range of 10-1000 ppm. The nanotubes grown with the electrolyte containing 2 vol % H2O offered the maximum response magnitude. For this stoichiometry, variation of corresponding length (1.25-2.4 µm) and wall thickness (19.8-9 nm) of the nanotubes was achieved by varying the anodization time (4-16 h) and temperatures (42-87 °C), respectively. While the variation of length influenced the sensing parameters insignificantly, the best response magnitude was achieved for ∼13 nm wall thickness. The underlying sensing mechanism was correlated with the experimental findings on the basis of structural parameters of the nanotubes.

Epidemiology of epilepsy and its burden in Kolkata, India.

BACKGROUND: Disability-adjusted life year (DALY) is a time-based measure of disease burden incorporating both disability and mortality. Our study aimed to determine the DALY lost from epilepsy in an Indian metropolis. METHODS: A population-based prospective study on epilepsy was conducted over 5 years (2003-8) in Kolkata, India, on randomly selected 100,802 subjects (males 53,209, females 47,593) to assess prevalence as well as to capture incident cases of epilepsy and those incident cases that died. Standard case definitions were used. The data were used to estimate years of life lost (YLL) due to premature mortality, years of life lived with disability (YLD), and DALY, utilizing the prevalence-based Global Burden of Disease (GBD) 2010 approach. Age- and gender-specific figures were computed. RESULTS: During 2003-2004, a total of 476 subjects with active epilepsy were detected and the age-adjusted prevalence rate was 4.71 per 1000. Over 5 years, there were 197 incident cases of epilepsy of whom 26 died. The age-adjusted annual incidence rate of epilepsy was 38.3 per 100,000. The all-cause standardized mortality rate (SMR) of epilepsy was 2.4. The burden of epilepsy in the year 2007-8 revealed the overall YLL was 755 per 100,000, and the overall YLD ranged from 14.45 to 31.0 per 100,000 persons depending on the clinical severity of the epilepsy. Both YLL and YLD values were higher in males than in females. The overall DALY lost due to epilepsy in 2007-8 was found to be 846.96 (males 1183.04, females 463.81) per 100,000. CONCLUSIONS: This is the first study in India to determine the DALY of epilepsy using GBD 2010. The results reveal a substantial burden of epilepsy in our setting. Similar such studies are needed in other parts of India in both urban and rural settings.

Ultrathin films of TiO2 nanoparticles at interfaces.

The properties of a material change remarkably as a result of the scaling dimensions. The Langmuir-Blodgett (LB) film deposition technique is known to offer precise control over the film thickness and the interparticle separation. To form a well-ordered LB film, it is essential to form a stable Langmuir film at the air-water interface. Here, we report our studies on ultrathin films of TiO2 nanoparticles at air-water and air-solid interfaces. The Langmuir film of TiO2 nanoparticles at the air-water interface was found to be very stable, and it exhibits loose-packing and close-packing phases. The LB films were transferred onto solid substrates for characterization and application. The surface morphology of the LB film was obtained by a field emission scanning electron microscope. The optical and electronic properties of the LB films of TiO2 nanoparticles were studied using UV-vis spectroscopy and current-voltage measurements, respectively. The LB film of TiO2 nanoparticles was employed for ethanol gas sensing, and the sensing performance was compared to that of bulk material. Because of the enormous gain in the surface to volume ratio and the increase in crystalline defect density in the ultrathin LB film of TiO2 nanoparticles, the LB film is found to be a potential functional layer for ethanol sensing as compared to the bulk material.

Sociocultural context of suicidal behaviour in the sundarban region of India.

The role of mental illness in nonfatal deliberate self-harm (DSH) is controversial, especially in Asian countries. This prospective study examined the role of psychiatric disorders, underlying social and situational problems, and triggers of DSH in a sample of 89 patients hospitalised in primary care hospitals of the Sundarban Delta, India. Data were collected by using a specially designed DSH register, Explanatory Model Interview Catalogue (EMIC), and clinical interview. Psychiatric diagnosis was made following the DSM-IV guidelines. The majority of subjects were young females (74.2%) and married (65.2%). Most of them (69.7%) were uncertain about their "intention to die," and pesticide poisoning was the commonest method (95.5%). Significant male-female differences were found with respect to education level, occupation, and venue of the DSH attempt. Typical stressors were conflict with spouse, guardians, or in-laws, extramarital affairs, chronic physical illness, and failed love affairs. The major depressive disorder (14.6%) was the commonest psychiatric diagnosis followed by adjustment disorder (6.7%); however 60.7% of the cases had no psychiatric illness. Stressful life situations coupled with easy access to lethal pesticides stood as the risk factor. The sociocultural dynamics behind suicidal behaviour and community-specific social stressors merit detailed assessment and timely psychosocial intervention. These findings will be helpful to design community-based mental health clinical services and community action in the region.

One-carbon metabolism factors and endometrial cancer risk.

BACKGROUND: This is the largest prospective cohort analysis to assess how dietary factors involved in one-carbon metabolism are associated with endometrial cancer incidence, using 26 years of follow-up data from the Nurses' Health Study. METHODS: The prospective cohort analysis of one-carbon metabolism dietary factors used the Cox proportional hazards model, and incorporated 788 incident endometrial cancer events from 1980 to 2006. Genotyping and unconditional logistic regression were performed on 572 endometrial cancer cases and their matched controls to examine 29 mostly non-synonymous single-nucleotide polymorphisms involved in one-carbon metabolism. RESULTS: There were no significant dose-response relationships between intake of any of the one-carbon metabolism dietary factors and endometrial cancer incidence, but alcohol consumption of <1 drink a day was significantly protective (hazard ratio: 0.80; 95% CI: 0.68, 0.94). Those with the MTHFR 677 TT or MTHFR 1298 CC genotype had more protective associations for many of the dietary factors and endometrial cancer, but statistical power was limited in this analysis. CONCLUSION: Dietary levels of folate, choline, methionine, vitamin B2, vitamin B6 or vitamin B12 do not appear to influence endometrial cancer incidence. Moderate alcohol intake may protect against developing endometrial cancer.

Comparative analysis between objective structured clinical examination (OSCE) and conventional examination (CE) as a formative evaluation tool in Pediatrics in semester examination for final MBBS students.

BACKGROUND: The use of objective structured clinical examination in pediatrics is not common in undergraduate evaluation process. OBJECTIVE: To evaluate the effectiveness of objective structured clinical examination as compare to conventional examination as formative assessment tool in Pediatrics. METHODS: We conducted a cross sectional comparative study in defined population of 9th semester MBBS students to evaluate the effectiveness of objective structured clinical examination as comparison to conventional examination as formative assessment tool in Pediatrics. We analyzed the perception of objective structured clinical examination among the students. RESULTS: Fifty-two students appeared for the objective structured clinical examination evaluation on the first day and 42 turned up for conventional examination on the next day. The 42 students who turned up for both examinations were asked to respond to the perception evaluation questionnaire. Comparison of the two examination styles showed that students fared better in objective structured clinical examination than in conventional examination both with respect to mean total score (p less than 0.001) as well as mean percentage score. Out of the 42 subjects who appeared in both examinations, all passed in objective structured clinical examination and 35 passed in conventional examination, this difference was significant by McNemar chi-square test (p = 0.016). 73.8% of the students opined in favor of objective structured clinical examination as a better formative assessment tool whereas 9.5% students preferred conventional examination. CONCLUSIONS: Objective structured clinical examination a statistically significant better evaluation tool with comparison to conventional examination.

Reduction in spinal-induced hypotension with ondansetron in parturients undergoing caesarean section: a double-blind randomised, placebo-controlled study.

BACKGROUND: Subarachnoid block is the preferred method of anaesthesia for caesarean section, but is associated with hypotension and bradycardia, which may be deleterious to both parturient and baby. Animal studies suggest that in the presence of decreased blood volume, 5-HT may be an important factor inducing the Bezold Jarisch reflex via 5-HT3 receptors located in intracardiac vagal nerve endings. In this study, we evaluated the effect of ondansetron, as a 5-HT3 receptor antagonist, on the haemodynamic response following subarachnoid block in parturients undergoing elective caesarean section. METHODS: Fifty-two parturients scheduled for elective caesarean section were randomly allocated into two groups. Before induction of spinal anaesthesia Group O (n=26) received intravenous ondansetron 4 mg; Group S (n=26) received normal saline. Blood pressure, heart rate and vasopressor requirements were assessed. RESULTS: Decreases in mean arterial pressure were significantly lower in Group O than Group S from 14 min until 35 min. Patients in Group O required significantly less vasopressor (P=0.009) and had significantly lower incidences of nausea and vomiting (P=0.049). CONCLUSION: Ondansetron 4 mg, given intravenously 5 min before subarachnoid block reduced hypotension and vasopressor use in parturients undergoing elective caesarean section.

Epidemiology of Parkinson disease in the city of Kolkata, India: a community-based study.

OBJECTIVE: No well-designed longitudinal study on Parkinson disease (PD) has been conducted in India. Therefore, we planned to determine the prevalence, incidence, and mortality rates of PD in the city of Kolkata, India, on a stratified random sample through a door-to-door survey. METHOD: This study was undertaken between 2003 to 2007 with a validated questionnaire by a team consisting of 4 trained field workers in 3 stages. Field workers screened the cases, later confirmed by a specialist doctor. In the third stage, a movement disorders specialist undertook home visits and reviewed all surviving cases after 1 year from last screening. Information on death was collected through verbal autopsy. A nested case-control study (1:3) was also undertaken to determine putative risk factors. The rates were age adjusted to the World Standard Population. RESULT: A total population of 100,802 was screened. The age-adjusted prevalence rate (PR) and average annual incidence rate were 52.85/100,000 and 5.71/100,000 per year, respectively. The slum population showed significantly decreased PR with age compared with the nonslum population. The adjusted average annual mortality rate was 2.89/100,000 per year. The relative risk of death was 8.98. The case-control study showed that tobacco chewing protected and hypertension increased PD occurrence. CONCLUSION: This study documented lower prevalence and incidence of PD as compared with Caucasian and a few Oriental populations. The mortality rates were comparable. The decreased age-specific PR among slum populations and higher relative risk of death need further probing.

A prospective study of suicidal behaviour in Sundarban Delta, West Bengal, India.

BACKGROUND: Deliberate self-harm is a challenging public health issue but there is a paucity of data on non-fatal deliberate self-harm in the literature. We aimed to understand the behaviour of deliberate self-harm, both fatal and nonfatal, in a primary care setting. METHODS: A year-long prospective study of all admitted patients of deliberate self-harm at 13 block primary health centres of the Sundarban region was done to examine the sociodemographic profile and clinical outcome of suicidal behaviour. Data were collected by using an especially devised deliberate self-harm register. Each subject was administered a 20-item case history sheet by trained medical officers and nursing staff. RESULTS: A total of 1614 deliberate self-harm subjects (619 men, 995 women) were admitted during the year, of whom 143 (62 men, 81 women) died. Although women, especially in the younger age groups, constituted the majority of subjects (61.6%), the fatality trend was higher among men than among women (10% v. 8.1%). Poisoning was the commonest (98.4%) method of self-harm, particularly using pesticide. Easy availability of pesticides was a risk factor. Psychosocial stressors, such as conflict with spouse, guardian or in-laws, failed love affairs and economic distress, were the common underlying reasons. The majority of acts of deliberate self-harm (92.6%) were committed inside the home, especially by women. Only a small proportion of subjects had a past or family history of attempt at deliberate self-harm. The overall incidence of fatal and non-fatal deliberate self-harm was 5.98 and 61.51 per 100 000 population, respectively. CONCLUSION: Both fatal and non-fatal pesticide-related deliberate self-harm is a major public health issue in the Sundarban region. An intersectoral approach involving primary health, administration and agriculture may help in developing an effective preventive programme to reduce the morbidity and mortality from deliberate self-harm.

Prevalence of essential tremor in the city of Kolkata, India: a house-to-house survey.

BACKGROUND AND PURPOSE: Prevalence of essential tremor (ET), one of the most common movement disorders, has not been properly evaluated amongst heterogeneous population in India. METHODS: We conducted a cross-sectional epidemiological study on the prevalence of ET in a randomly stratified population in the metropolitan city of Kolkata (erstwhile Calcutta), India, by a field team headed by a specialist doctor. A two-stage house-to-house survey was carried out with a validated screening instrument. RESULTS: A population of 52377 was screened and a total of 184 cases of ET were identified as per pre-defined criteria and the prevalence rate adjusted to World Standard Population was 3.95 per 1000 (95% CI: 3.40-4.56). Age-specific prevalence showed increasing prevalence with aging. Sex-specific prevalence did not show significant difference between men and women. Socio-economic factors appeared to influence the prevalence and risk of ET was higher amongst slum dwellers versus non-slum population (odd ratio-2.29). Family history was positive in about one-fifth of the cases. CONCLUSION: This study has documented that the prevalence of ET above 40 years in India is similar to that of many countries globally and common amongst slum dwellers and there are fewer familial cases.