RESEARCH BMJ: first published as 10.1136/bmj.c4974 on 27 September 2010. Downloaded from Sociodemographicpatterningofnon-communicabledisease risk factors in rural India: a cross sectional study Sanjay Kinra, senior lecturer,1 Liza J Bowen, research degree student,1 Tanica Lyngdoh, research fellow,2 Dorairaj Prabhakaran, adjunct professor,2 Kolli Srinath Reddy, president,3 Lakshmy Ramakrishnan, associate professor,4 Ruby Gupta, research fellow,4 Ankalmadagu V Bharathi, lecturer,5 Mario Vaz, senior lecturer,5 Anura V Kurpad, professor,5 George Davey Smith, professor,6 Yoav Ben-Shlomo, professor,6 Shah Ebrahim, professor1 1Non-communicable Disease ABSTRACT Conclusions The prevalence of most risk factors was Epidemiology Unit, London School Objectives To investigate the sociodemographic generally high across a range of sociodemographic of Hygiene and Tropical Medicine, London WC1E 7HT, UK patterning of non-communicable disease risk factors in groups in this sample of rural villagers in India; in 2Centre for Chronic Disease rural India. particular, the prevalence of tobacco use in men and Control, New Delhi, India Design Cross sectional study. obesity in women was striking. However, given the 3Public Health Foundation of Setting About 1600 villages from 18 states in India. Most limitations of the study (convenience sampling design India, New Delhi, India were from four large states due to a convenience sampling and low response rate), cautious interpretation of the 4 Department of Biochemistry, All strategy. results is warranted. These data highlight the need for India Institute of Medical Sciences, Delhi, India Participants 1983 (31% women) people aged 20–69 years careful monitoring and control of non-communicable 5St John’s Research Institute, (49% response rate). disease risk factors in rural areas of India. Bangalore, India Main outcome measures Prevalence of tobacco use, 6 Department of Social Medicine, alcohol use, low fruit and vegetable intake, low physical INTRODUCTION University of Bristol, Bristol activity, obesity, central adiposity, hypertension, The current epidemic of non-communicable diseases http://www.bmj.com/ Correspondence to: S Kinra [email protected] dyslipidaemia, diabetes, and underweight. in India is attributed to increased longevity and life- Results Prevalence of most risk factors increased with style changes resulting from urbanisation.12 However, Cite this as: BMJ 2010;341:c4974 age. Tobacco and alcohol use, low intake of fruit and doi:10.1136/bmj.c4974 recent data suggest that non-communicable diseases vegetables, and underweight were more common in lower are already the commonest cause of death in some socioeconomic positions; whereas obesity, parts of rural India.3-5 This is plausible as, apart from dyslipidaemia, and diabetes (men only) and hypertension improvements in life expectancy, the greater inter- (women only) were more prevalent in higher connectedness increasingly allows rural populations on 2 October 2021 by guest. Protected copyright. socioeconomic positions. For example, 37% (95% CI 30% to adopt urban lifestyles without migration to urban to 44%) of men smoked tobacco in the lowest areas.5-7 A rise in the prevalence of non-communicable socioeconomic group compared with 15% (12% to 17%) disease risk factors in rural areas has important public in the highest, while 35% (30% to 40%) of women in the health implications, since, notwithstanding the rapid highest socioeconomic group were obese compared with urbanisation, two thirds of India’s one billion popula- 13% (7% to 19%) in the lowest. The age standardised tion still lives in rural areas.8 Rural populations have prevalence of some risk factors was: tobacco use (40% limited access to health care and can least afford to (37% to 42%) men, 4% (3% to 6%) women); low fruit and pay for the high treatment costs associated with chronic vegetable intake (69% (66% to 71%) men, 75% (71% to conditions. 78%) women); obesity (19% (17% to 21%) men, 28% Several surveys have examined the prevalence of (24% to 31%) women); dyslipidaemia (33% (31% to risk factors for non-communicable disease in urban 36%) men, 35% (31% to 38%) women); hypertension India, but recent data from rural India are sparse.9-12 (20% (18% to 22%) men, 22% (19% to 25%) women); Those that exist are limited to selected locations (invari- diabetes (6% (5% to 7%) men, 5% (4% to 7%) women); ably chosen within a convenient distance of an urban and underweight (21% (19% to 23%) men, 18% (15% to centre) or risk factors and do not allow systematic 21%) women). Risk factors were generally more prevalent examination of nationally representative socio- in south Indians compared with north Indians. For demographic patterns.5 13-19 Knowing the sociodemo- example, the prevalence of dyslipidaemia was 21% (17% graphic patterns of non-communicable disease risk to 33%) in north Indian men compared with 33% (29% to factors across rural India is important not only for pre- 38%) in south Indian men, while the prevalence of obesity dicting the future course of the epidemic and planning was 13% (9% to 17%) in north Indian women compared relevant policies for prevention and disease control, but with 24% (19% to 30%) in south Indian women. may also provide new aetiological insights through BMJ | ONLINE FIRST | bmj.com page 1 of 9 RESEARCH their juxtaposition to known variations in disease pat- appropriate measure of socioeconomic position in BMJ: first published as 10.1136/bmj.c4974 on 27 September 2010. Downloaded from terns (such as higher disease prevalence reported from rural India, where the joint family structure of the south India).20 21 household renders an individual’s own socioeconomic The Indian Migration Study was established to position less important. The full index has a large num- investigate the effects of rural-urban migration by ber of items (29 in total), but we restricted this to 13 using a sibling pair design to collect data on migrant items by selecting a priori the ones we believed to be urban factory workers and their co-resident spouses most informative. We subsequently validated the short and their non-migrant rural dwelling siblings.22 We index against the full standard of living index using the carried out a secondary analysis of data on the rural dataset of the second National Family Health Survey participants of this study to examine the prevalence NFHS-2 (the national demographic survey of India of non-communicable disease risk factors by age, sex, involving 91 117 households).24 The short index classi- socioeconomic position, and geographical location of fied 98.5% (n=89 716) of the survey participants in the the participants. We hypothesised that the prevalence same or adjacent fifth of the full index (66% in the same of risk factors would increase with age and socioeco- fifth), with only 1.5% (n=1401) falling outside this nomic position, and be relatively higher among men range (κ statistic 0.58); there was no evidence for an and south Indians. urban-rural bias in classification. Participants were asked about their current tobacco METHODS use in any form (smoked or chewed on a daily basis in Study population the previous six months), and regular consumption of The Indian Migration Study was nested within a alcohol (on ≥10 days a month in the previous six cardiovascular risk factor surveillance system, which months). monitors risk factors in industry populations across A quantitative food frequency questionnaire was several large cities in India.12 Factory sites in four developed, based on methods described elsewhere,25 large cities (Lucknow, Nagpur, Hyderabad, and Ban- and used to collect data on food intake (including galore) were chosen to sample populations from the fruit and vegetables) over the previous year. For seaso- north, centre, and south of the country.22 Factory work- nal foods, intake during the appropriate seasons was ers and their co-resident spouses were surveyed using estimated. The questionnaire was developed to cover employer records as a sampling frame and recruited to the different dietary behaviours in all of the regions the study if they had migrated from a rural area. Each included in the study, and specific recipes for regions participant (factory worker or spouse) was asked to and rural and urban settings were collected to account invite one non-migrant full sibling of the same sex for differences in food preparation between areas. and closest to them in age still residing in their rural A quantitative physical activity questionnaire speci- http://www.bmj.com/ place of origin. Precedence was given to sex over age, fic to the Indian population was developed using meth- and when multiple same sex siblings were available the ods described previously,22 and subsequently one closest in age was invited. In a small number of validated against reference methods in both rural and cases where no rural sibling was available (<5%), a cou- urban Indians.26 The questionnaire is used to gather sin or a close friend from the same village was invited. information on participants’ habitual daily physical There were no other exclusion criteria at this recruit- activity based on involvement in potential active and ment stage. This convenience sampling strategy passive activities (occupational, household, hobby, on 2 October 2021 by guest. Protected copyright. resulted in rural dwelling siblings being drawn from exercise, sedentary, travel, etc) and their duration and anywhere in the country (18 of the 28 states), although frequency over the previous month. Each reported a substantial proportion came from the four large states activity was assigned a MET (metabolic equivalent of in which the factories were based, reflecting the migra- task) score based on the Compendium of Physical tion patterns of the factory workers and their spouses. Activities, which is the energy cost of the activity The fieldwork took place between March 2005 and expressed as multiples of the basal metabolic rate December 2007.