Development and testing of a quantitative food frequency questionnaire for use in Gujarat, India

OBJECTIVE

To develop and test a quantitative, interviewer-administered food frequency questionnaire (FFQ) to ascertain nutrient intakes of individuals in northern India.

DESIGN

A 92-item FFQ was developed based on food use and market surveys of the study area. A validation study was conducted consisting of 24-h diet recalls (24HR) administered on 6 randomly selected days over 1 year. Two FFQs were administered, one each at the beginning and end of the 1-year period. FFQ and 24HR-derived nutrient scores were compared using correlation and regression analyses and by computing differences between nutrient intakes estimated by the two methods.

SETTING

Rural villages in Bhavnagar District, Gujarat, North India.

SUBJECTS

60 individuals who agreed to provide all necessary data.

RESULTS

Pearson (parametric) correlation coefficients averaged 0.69 in comparing nutrient scores derived from the 24HR with those from the first FFQ and 0.72 in comparing the second FFQ (P<0.0001). Spearman correlation coefficients were virtually identical to the Pearson correlations, averaging 0.68 and 0.72, respectively. In regression analyses, most coefficients were close to 1.0 (perfect linear association). Nutrient scores were significantly and consistently higher on both FFQs relative to the 24HR.

CONCLUSIONS

This FFQ produces results broadly comparable, and superior in some respects, to those commonly used in the West. Higher than average measures of association indicate its suitability for comparing exposures within this study population in reference to health-related endpoints.

Oral mucosal lesions associated with betel quid, areca nut and tobacco chewing habits: consensus from a workshop held in Kuala Lumpur, Malaysia, November 25-27, 1996

A variety of betel/areca nut/tobacco habits have been reviewed and categorized because of their possible causal association with oral cancer and various oral precancerous lesions and conditions, and on account of their widespread occurrence in different parts of the world. At a recent workshop in Kuala Lumpur it was recommended that "quid" be defined as "a substance, or mixture of substances, placed in the mouth or chewed and remaining in contact with the mucosa, usually containing one or both of the two basic ingredients, tobacco and/or areca nut, in raw or any manufactured or processed form." Clear delineations on contents of the quid (areca nut quid, tobacco quid, and tobacco and areca nut quid) are recommended as absolute criteria with finer subdivisions to be added if necessary. The betel quid refers to any quid wrapped in betel leaf and is therefore a specific variety of quid. The workshop proposed that quid-related lesions should be categorized conceptually into two categories: first, those that are diffusely outlined and second, those localized at the site where a quid is regularly placed. Additional or expanded criteria and guidelines were proposed to define, describe or identify lesions such as chewer's mucosa, areca nut chewer's lesion, oral submucous fibrosis and other quid-related lesions. A new clinical entity, betel-quid lichenoid lesion, was also proposed to describe an oral lichen planus-like lesion associated with the betel quid habit.

Pseudoaneurysm of subclavian artery--atypical presentation

We present a rare case of pseudoaneurysm of right subclavian artery who presented with supraclavicular mass. Injury of the subclavian artery causing pseudoaneurysm is a serious surgical emergency and a surgical intervention is indicated.

Dietary factors in oral leukoplakia and submucous fibrosis in a population-based case control study in Gujarat, India

OBJECTIVES

To investigate the relationship of specific nutrients and food items with oral precancerous lesions among tobacco users.

DESIGN

A population-based case-control study.

SETTING

Villages in Palitana taluk of Bhavnagar district, Gujarat, India.

SUBJECTS AND METHODS

An interviewer-administered food frequency questionnaire, developed and validated for this population, was used to estimate nutrient intake in blinded, house-to-house interviews. Among 5018 male tobacco users, 318 were diagnosed as cases. An equal number of controls matched on age (+/- 5 years), sex, village, and use of tobacco were selected.

MAIN OUTCOME MEASURES

Odds ratios (OR) from multiple logistic regression analysis controlling for relevant variables (type of tobacco use and economic status).

RESULTS

A protective effect of fibre was observed for both oral submucous fibrosis (OSF) and leukoplakia, with 10% reduction in risk per g day-1 (P < 0.05). Ascorbic acid appeared to be protective against leukoplakia with the halving of risk in the two highest quartiles of intake (versus the lowest quartile: OR = 0.46 and 0.44, respectively; P < 0.10). A protective effect of tomato consumption was observed in leukoplakia and a suggestion of a protective effect of wheat in OSF.

CONCLUSION

In addition to tobacco use, intake of specific nutrients may have a role in the development of oral precancerous lesions.

Prevalence of respiratory symptoms, bronchial hyperreactivity, and asthma in a megacity. Results of the European community respiratory health survey in Mumbai (Bombay)

To estimate adult asthma prevalence in the world's most rapidly growing mega-city, we applied epidemiologic surveillance tools, as a cooperating center of the European Community Respiratory Health Survey, to a randomly selected sample of Mumbai (Bombay) residents in 1992 through 1995. From a metropolitan population of over 10 million, we took a one-in-ten random sample from electoral rolls in a socially diverse residential district, and examined asthma symptoms in adults age 20 to 44 yr. In Phase I, we interviewed 2,313 adults about symptoms, asthma diagnosis, and medications in the previous 12 mo. In Phase II, family and smoking history, socioeconomic data, housing characteristics, serum IgE, allergy skin tests, spirometry, and methacholine challenge tests were obtained in a subset of 20% of those who had completed Phase I. House dust mite was the most common positive skin test (18% prevalence) and the only one of the nine applied that was significantly associated with asthma symptoms and physician-diagnosed asthma. Asthma prevalence was 3.5% by physician diagnosis, and 17% using a very broad definition including those with asymptomatic bronchial hyperreactivity. Asthma prevalence was strongly associated with positive house dust mite skin test, family history of asthma, and total IgE.

Development and testing of a quantitative food frequency questionnaire for use in Kerala, India

OBJECTIVE

To develop and test a food frequency questionnaire (FFQ) for use in rural areas of Kerala, India.

DESIGN

Based on food use and market surveys of the study area, a quantitative 81-item interviewer-administered FFQ was developed. A validation study was conducted consisting of 24-h diet recalls (24HR) administered on 8 days randomly selected over an entire year and two administrations of the FFQ, one at the beginning of the 1-year period and the other at the end. FFQ and 24HR-derived nutrient scores were compared using correlation and regression analyses and by examining differences in the nutrient scores.

SETTING

Rural villages in Ernakulum district, Kerala, South India.

SUBJECTS

In each of 30 households, the male head of household and female food preparer were enrolled.

RESULTS

Pearson (parametric) correlation coefficients (r(p)) averaged about 0.50 in comparing nutrient scores derived from the 24HR with those from the first FFQ and about 0.55 in comparing the second FFQ. On average, Spearman correlation coefficients (r(s)) were slightly lower than the r(p) in comparing the scores derived from the first FFQ, but virtually identical for the second FFQ. Regression analyses indicated better agreement in the comparison of the 24HR-derived scores with the first FFQ than the second FFQ. Difference scores, however, tended to be larger in comparing the first FFQ scores with the 24HR.

CONCLUSIONS

This FFQ produces results broadly comparable to those used in Europe and North America, indicating its suitability for comparing exposures within a study population in reference to health-related endpoints.

Oral submucous fibrosis in India: a new epidemic?

BACKGROUND

Oral submucous fibrosis (OSF) is a precancerous condition caused by use of the areca nut. The reported prevalence of OSF in Bhavnagar district during 1967 was 0.16%. We investigated whether the impression of an increase in the incidence of the disease was real.

METHODS

A house-to-house survey was conducted in Bhavnagar district, Gujarat state. The use of areca nut-containing products and tobacco was assessed through an interviewer administered questionnaire. The oral examination was done by dentists. The diagnostic criteria for OSF was the presence of palpable fibrous bands.

RESULTS

A total of 11,262 men and 10,590 women aged 15 years and older were interviewed for their tobacco habits. Among 5018 men who reported the use of tobacco or areca nut, 164 were diagnosed as suffering from OSF. All but four cases were diagnosed among 1786 current areca nut users (age-adjusted relative risk: 60.6). Areca nut was used mostly in mawa, a mixture of tobacco, lime and areca nut, and 10.9% of mawa users had OSF (age-adjusted relative risk: 75.6). The disease as well as areca nut use was concentrated (about 85%) in the lower (< 35 years) age group.

CONCLUSIONS

An increase in the prevalence of OSF, especially in the lower age groups, directly attributable to the use of areca nut products was observed. This could lead to an increase in the incidence of oral cancer in the future.

p53 expression in oral precancer as a marker for malignant potential

The potential of p53 protein expression as a marker for determining which oral precancerous lesions may transform to malignancy with time was assessed. We compared the p53 expression in archival formalin-fixed, paraffin-embedded tissues from 22 baseline biopsies of precancerous lesions that transformed to cancer in 4-25 years against that in 68 similar lesions that did not transform over the same time period. Twenty-nine percent of precancers that transformed were p53-positive at baseline, compared to 31% of the biopsies that did not transform to malignancy. When examined by immunohistochemical methods p53 expression failed to detect potential malignant status of oral precancer. Non-specificity of the assay may account for this result but overexpression of p53 due to DNA damage by tobacco/betel-quid in non-progressive lesions needs further study. Nine precancerous lesions became p53-immunoreactive from precancer to cancer. This may suggest p53 overexpression peaks close to the time of transition from precancer to cancer rather than early in the natural history of oral precancer.

Correlation of the anatomical distribution of venous reflux with clinical symptoms and venous haemodynamics in primary varicose veins

AIM

The aim of this study was to correlate the anatomical distribution of venous reflux with clinical symptoms and venous haemodynamics in patients with primary varicose veins.

METHODS

Venous reflux was examined using duplex colour Doppler ultrasonography in 266 legs in 191 patients. The venous refilling and reflux times were also measured.

RESULTS

Of the 266 legs, 82 per cent had reflux in the long saphenous vein (LSV), 26 per cent in the short saphenous vein (SSV), 62 per cent had incompetent perforators (IPs) in the calf and 48 per cent had reflux in the deep veins. LSV reflux combined with SSV reflux and/or IPs was associated significantly with severe venous disease and abnormal venous haemodynamics. Femoropopliteal reflux played a role in the development of venous eczema and ulcers when combined with superficial venous reflux.

CONCLUSION

Patients at high risk of developing complications of venous disease may be identified by an accurate non-invasive evaluation of reflux patterns.

A national epidemiological survey of oral mucosal lesions in Malaysia

The prevalence of oral mucosal lesions in Malaysia was determined by examining a representative sample of 11,707 subjects aged 25 years and above throughout the 14 states over a period of 5 months during 1993/1994. A two-stage stratified random sampling was undertaken. A predetermined number of enumeration blocks, the smallest population unit in the census publication, was selected from each state. With the selected enumeration block, a systematic sample of living quarters was chosen with a random start. The survey instrument included a questionnaire on sociodemographic characteristics and a clinical examination. The clinical examination was carried out by 16 specially trained dental public health officers and the diagnosis calibrated with a final concordance rate of 92%. The age in the sample ranged from 25 to 115 years with a mean of 44.5+/-14.0. The sample comprised 40.2% males and 59.8% females; 55.8% were Malays, 29.4% Chinese, 10.0% Indians and 1.2% other ethnic groups. Oral mucosal lesions were detected in 1131 (9.7%) subjects, 5 (0.04%) had oral cancer, 165 (1.4%) had lesions or conditions that may be precancerous (leukoplakia, erythroplakia, submucous fibrosis and lichen planus) and 187 (1.6%) had betel chewer's mucosa. The prevalence of oral precancer was highest amongst Indians (4.0%) and other Bumiputras (the indigenous people of Sabah and Sarawak) (2.5%) while the lowest prevalence was amongst the Chinese (0.5%).

Survey of sociodemographic characteristics of tobacco use among 99,598 individuals in Bombay, India using handheld computers

OBJECTIVES

To study the diversity and sociodemographic characteristics of tobacco use in Bombay, India.

DESIGN

Population-based, cross-sectional, house-to-house survey with face-to-face interviews in the city of Bombay during 1992-94. Data was input directly into a programmed, handheld computer (electronic diary).

PARTICIPANTS

Permanent residents of the city of Bombay aged 35 years and older.

MAIN OUTCOME MEASURES

Tobacco use in various smoking and smokeless forms.

RESULTS

99598 individuals were interviewed (60% women, 40% men). Among women, prevalence of tobacco use was high (57.5%) but almost solely in the smokeless form. Among men, 69.3% reported current tobacco use and 23.6% were smokers. The most common smokeless tobacco practice among women was mishri use (44.5% of smokeless users) and among men betel quid with tobacco (27.1%). About half of smokers used bidi and half smoked cigarettes. Chewing areca nut without tobacco was rare (< 0.5% of smokeless users). Educational level was inversely associated with tobacco use of all kinds except cigarette smoking.

CONCLUSIONS

The pattern of tobacco use varies across India and, in Bombay, is very different from other areas. Using handheld computers to collect data in the field was successful.

Epidemiology of cancer by tobacco products and the significance of TSNA

Globally, oral cancer is one of the ten common cancers. In some parts of the world, including the Indian subcontinent, oral cancer is a major cancer problem. Tobacco use is the most important risk factor for oral cancer. The most common form of tobacco use, cigarette smoking, demonstrates a very high relative risk--in a recent cohort study (CPS II), even higher than lung cancer. In areas where tobacco is used in a smokeless form, oral cancer incidence is generally high. In the West, especially in the U.S. and Scandinavia, smokeless tobacco use consists of oral use of snuff. In Central, South, and Southeast Asia smokeless tobacco use encompasses nass, naswar, khaini, mawa, mishri, gudakhu, and betel quid. In India tobacco is smoked in many ways; the most common is bidi, others being chutta, including reverse smoking, hooka, and clay pipe. A voluminous body of research data implicating most of these forms of tobacco use emanates from the Indian subcontinent. These studies encompass case and case-series reports, and case-control, cohort, and intervention studies. Collectively, the evidence fulfills the epidemiological criteria of causality: strength, consistency, temporality, and coherence. The biological plausibility is provided by the identification of several carcinogens in tobacco, the most abundant and strongest being tobacco-specific N-nitrosamines such as N-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). These are formed by N-nitrosation of nicotine, the major alkaloid responsible for addiction to tobacco. The etiological relationship between tobacco use and oral cancer has provided us with a comprehensive model for understanding carcinogenesis.

Etiology of oral submucous fibrosis with special reference to the role of areca nut chewing

Oral submucous fibrosis (OSF) is a high risk precancerous condition, predominantly affecting Indians. Consumption of chilli was hypothesized as an etiologic factor on the basis of ecological observations and a solitary animal experimental study. Subsequent epidemiologic studies that included case-series reports, large cross-sectional surveys, case-control studies, cohort and intervention studies have identified areca nut as the major etiologic agent. Tissue-culture studies involving human fibroblasts, areca nut extracts and areca nut alkaloids supported this etiologic hypothesis by showing fibroblastic proliferation and increased collagen formation. Currently, the role of genetic susceptibility and that of autoimmunity are receiving attention. The influence of nutritional factors, if any, remains unclear.

Effect of cessation of tobacco use on the incidence of oral mucosal lesions in a 10-yr follow-up study of 12,212 users

OBJECTIVE

To study the effect of cessation of tobacco use on the incidence of lichen planus, leukoplakia and other oral mucosal lesions.

DESIGN

A 10-yr cohort study in a rural population of Ernakulam district, Kerala, India.

MATERIAL AND METHODS

Some 12,212 tobacco users were interviewed and examined in a baseline survey and re-examined annually for 10 years. At each examination they were exposed to health educational programs to encourage them to quit their tobacco use. The incidence rates were calculated using person-years method among those who stopped their tobacco use and all others.

RESULTS

A total of 77,681 person-years of observation accrued among men and 32,544 among women. Among men 6.5% of these and among women 14.4% were in the stopped category. The incidence of oral lichen planus did not show any consistent association with cessation of tobacco habits (incidence ratio 1.35) but for leukoplakia there was a substantial drop in the incidence after cessation (incidence ratio 0.31). Several other tobacco-associated oral mucosal lesions such as oral lichen planus-like lesion, smoker's palate, preleukoplakia, central papillary atrophy of the tongue and leukoedema showed either zero, or very small incidence, after cessation.

CONCLUSION

The reported association between tobacco use and lichen planus appears to be indirect but for all other lesions it is direct. The cessation of tobacco use led to a substantial fall in the incidence of leukoplakia and other lesions implying a reduced risk for oral cancer after cessation of tobacco use.

Cancer deaths in India: is the model-based approach valid?

The model-based cancer mortality estimates for India (775,800) are nearly double the data-based estimates (433,000), and are higher than even the incidence estimates (612,300). The model-based approach is therefore, at least in the case of India, incorrect. Established practice is to use real data to validate theoretical models, not to reject the data if apparently the model does not fit.

An approach to consumer feedback in an out-patient specialty service

Details an approach to consumer feedback in an out-patient specialty service. Outlines the approach to undertaking a consumer survey and how feedback from people using the Genito-Urinary Medicine services can be obtained. The aim of the survey was to assess the level of individual/personal care. Gives the objectives and methodology, main findings and recommendations, together with a cost benefit analysis of the work.

Primary prevention trial of oral cancer in india: a 10-year follow-up study

Oral cancer is caused by chewing and smoking of tobacco. To assess the feasibility of primary prevention of oral cancer, two cohorts were studied in base-line surveys and then followed up annually for 10-yr in Ernakulam district of Kerala state. The intervention cohort consisted of 12212 tobacco users aged 15 yr and over, who were exposed to a concentrated program of education against tobacco use. The control cohort was a non-concurrent cohort of 6075 tobacco users studied using similar methods but with a minimal amount of advice against tobacco use. The stoppage of tobacco use increased and the incidence rate of leukoplakia decreased significantly and substantially in the intervention cohort compared to the control cohort. The decrease in the incidence of leukoplakia was indicative of the decrease in the risk of oral cancer since the two were intimately related. This study demonstrated feasibility of primary prevention of oral cancer.