- Research article
- Open Access
- Open Peer Review
Oral health behavior patterns among Tanzanian university students: a repeat cross-sectional survey
© Åstrøm and Masalu; licensee BioMed Central Ltd. 2001
- Received: 1 November 2001
- Accepted: 21 December 2001
- Published: 21 December 2001
This study examines oral health behavioral trends and the development of sociodemographic differences in oral health behaviors among Tanzanian students between 1999 and 2000.
The population targeted was students attending the Muhimbili University College of Health Sciences (MUCHS) at the University of Dar es Salaam (UDSM), Dar es Salaam, Tanzania. Cross-sectional surveys were conducted and a total of 635 and 981 students, respectively, completed questionnaires in 1999 and 2001.
Cross-tabulation analyses revealed that in 1999, the rates of abstinence from tobacco use, and of soft drink consumption, regular dental checkups, and intake of chocolate/candy were 84%, 51%, 48%, and 12%, respectively, among students of urban origin and 83%, 29%, 37%, and 5% among their rural counterparts. The corresponding rates in 2001 were 87%, 56%, 50%, and 9% among urban students and 84%, 44%, 38%, and 4% among rural ones. Multiple logistic regression analyses controlling for sex, age, place of origin, educational level, year of survey, and their interaction terms revealed a significant increase in the rate of soft drink consumption, implementation of oral hygiene measures, and abstinence from tobacco use between 1999 and 2001. Social inequalities observed in 1999, with urban students being more likely than their rural counterparts to take soft drinks and go for regular dental checkups, had leveled off by 2001.
This study provides initial evidence of oral health behavioral trends, that may be utilized in the planning of preventive programs among university students in Tanzania.
- Oral Health
- Soft Drink
- Urban Student
- Oral Health Behavior
- Soft Drink Consumption
In socioeconomically developing countries, the change from a traditional lifestyle to a Western lifestyle has, among other things, led to an increase in sugar consumption from food and beverages, and in the form of chocolate/candy . Higher caries prevalence is anticipated following increased consumption of sugar especially since for the majority, fluoridated toothpaste is not easily available. In Tanzania, liberalization of trade links with industrialized countries has brought about imports of greater quantities of sugar; also, commercialized sugar products have increasingly gained social importance . There is evidence suggesting that commercialized sugar products are very popular, particularly among affluent urban residents. Moreover, a marked decline in the sale of tobacco in the industrialized world seems to have been compensated by a rapid development of a new generation of smokers in sub-Saharan Africa . In recent years, smoking has become fashionable and an increasing number of smoking women is anticipated. Researchers' and the general public's opinion about the developmental patterns of tobacco use and sugar intake appears, however, based more on anecdote than on scientific evidence. So far, few systematic data are available on health behavioral trends among the people of Tanzania and its neighboring countries.
Although behavioral research with relevance to health is scarce in sub-Saharan Africa, some studies, commonly of cross-sectional design, have been undertaken during the past 10–15 years. Today still, moderate numbers of youth confirm daily intake of commercialized sugar products [4–7]. Contrary to what has been observed in occidental studies , female and urban respondents report snacking of sugared foods and drinks more frequently than do their male and rural counterparts . Recent studies of adolescents in Tanzania and Zimbabwe have yielded lifetime prevalence rates of tobacco use, ranging from 0.4% to 12% and from 12% to 27% in females and males, respectively [10, 11]. In a repeat cross-sectional study of Nigerian university students, Adelekan et al.  report on a decline in lifetime prevalence use of cigarettes from 37% in 1988 to 21% in 1993. Flisher et al.  report on a prevalence of current smoking of 18% among high-school students in the Cape Peninsula, Cape Town, South Africa. Surveys of adolescents and young adults have shown that the majority of them, and more females than males, engage in daily tooth cleaning [4, 5]. Mosha and Scheutz  report a lifetime prevalence of regular dental checkups in the general adult Tanzanian population, amounting to 51% among men and 43% among women.
Statistics on change in oral health-related behaviors across time may provide a valuable tool in the planning, implementation, and evaluation of oral health promotion programs. Just as important, from an oral health educational point of view, is information regarding the socioeconomic and regional distribution of oral health-related behaviors. A basic principle in the diffusion of new lifestyles is the spread from higher to lower socioeconomic status groups, from people with higher education to the less educated, and from people exposed to mass media to those who are not exposed or who are less exposed . In sub-Saharan Africa, university students constitute a relatively homogenous, socially affluent group within the general adult population. As such, they are important as early adopters of new ideas and Western lifestyles. This study aims to examine trends in oral health-related behavior among university students in Tanzania and to study the development of socioeconomic and regional differences in students' oral health-related behaviors between 1999 and 2001.
Sample and data collection
Frequency distribution of participants by sociodemographic characteristics and survey year.
1999 n = 635c (%)
2001 n = 981c (%)
Higher degree studentsa
Lower degree/diploma studentsb
Age: 19–25 yrs
Age: >25 yrs
Raised in an urban environment
Raised in a rural environment
Ever used tobacco products was assessed using the response categories (1) "No", (0) "yes". Consumption of soft drinks, chocolate/candy, and sugared coffee/tea and use of toothpicks were assessed on a 6-point scale, where (1) = "more than once a day", (2) = "once a day", (3) = "3–6 times a week", (4) = "1–2 times a week", (5) = "rarely", and (6) = "never". Frequency of dental checkups was assessed on a 4-point scale, with (1) = "twice a year", (2) = "once a year", (3) = "rarely", and (4) = "never". For cross-tabulation and logistic regression analysis, dummy variables were constructed yielding the categories (1) "at least several times a week", and (0) "rarely/never" with respect to consumption of sugared snacks and drinks. Use of toothpicks and frequency of dental checkups were dichotomized yielding the categories (1) "at least daily" and (0) "less than once a day", and (1) "at least once a year" and (0) "less than once a year", respectively. Demographic information included sex: (1) female or (2) male; place of origin: (1) city/town or (2) village/rural; age at last birthday: (1) 19–25 years or (2) >25 years; educational level: (1) lower degree/diploma (Institute of Allied Health Sciences) or (2) higher degree (faculties of Medicine, Dentistry, Pharmacy, and Nursing).
Cross-tabulation analyses and chi-square statistics were used to assess bivariate relationships between oral health-related behavior and sociodemographic characteristics (age, sex, educational level, and place of origin). Time trends, from 1999 to 2001, were estimated using logistic regression analyses with year of data collection as a categorical variable and by calculating the average odds ratio (OR) for the 2-year survey period. Stepwise multiple regression analyses were performed using the logit model, with 95% confidence intervals (CIs) given for the ORs indicating statistically significant relationships if both values are either greater or less than 1. All independent variables, survey year (1999/2001), age, sex, place of origin, and educational level, and their corresponding interaction terms were checked by logistic regression analysis. The significance of adding a variable or an interaction term into the model was tested with Pearson's chi-square test (P < 0.05).
The sex distribution differed significantly with age, place of origin, and educational level within each survey year (P < 0.001). As summarized in Table 1, the 1999 and 2001 samples were relatively homogenous although significantly higher proportions of students surveyed in 2001 as compared with those surveyed in 1999 were 19–25 years old and enrolled at educational institutions offering higher degree courses (P < 0.001).
Frequency distribution (percentage %) of students by weekly intake of soft drinks, sugared coffee tea, and chocolate/candy and by place of origin and sex, 1999–2001.
n = 421 (%)
n = 185 (%)
n = 236 (%)
n = 207 (%)
n = 48(%)
n = 159(%)
Frequency distribution (percentage %) of students reporting total abstinence from tobacco use, weekly use of toothpicks, and annual dental checkups by place of origin and sex, 1999–2001.
Total n = 421 (%)
Female n = 185 (%)
Male n = 236 (%)
Total n = 207 (%)
Female n = 48 (%)
Male n = 159 (%)
Never use tobacco
124 (79) *
76 (37) *
52 (32) *
Never use tobacco
203 (80) **
78 (30) **
Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for students' intake of soft drinks, chocolate/candy, and sugared coffee/tea, and use of toothpicks, according to sex, place of origin, age, educational level, and year of survey.
Female vs male
19–25 yrs vs >25 yrs
Place of residence
Urban vs rural
Higher vs lower
2001 vs 1999
Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for students' dental checkups and reported abstinence from tobacco products, according to sex, place of origin, age, educational level, and year of survey.
Never use of tobacco
Female vs male
19–25 yrs vs >25 yrs
Place of residence
Urban vs rural
Higher vs lower
2001 vs 1999
Significant second-order effects on soft drink consumption in terms of regression coefficients (B) were shown for the terms survey year by place of origin (B = 0.56; P < 0.05) and survey year by age group (B = 0.53; P < 0.05). Probing the results of logistic regression analysis in each survey year highlighted the nature of the interaction terms. The OR for urban students as compared with students from a rural area (OR = 1) decreased from 2.7 (95% CI 1.8–4.0) in 1999 to 1.6 (95% CI 1.2–2.1) in 2001. Compared with 1999 (OR = 1), the ORs for taking soft drinks in 2001 were 1.1 (95% CI 0.8–1.4) and 2.0 (95% CI 1.4–2.9) among urban and rural-origin students, respectively. The OR for the 19–25-year-olds (reference category: >25 years old) changed from 1.2 (95% CI 0.8–1.9) in 1999 to 0.7 (95% CI 0.5–0.9) in 2001. Finally, the ORs for soft drink consumption in 2001 (reference category: 1999) was 1.9 (95% CI 1.2–2.8) among students above 25 years old. Among the 19–25-year-old students, there was no significant change in soft drink consumption between 1999 and 2001.
Significant second-order effects on chocolate/candy consumption and dental checkups were observed for the terms survey year by age (B = 1.4; P < 0.05) and survey year by educational level (B = 0.5; P < 0.05). Separate regression analyses in each survey year showed a reversal of the age distribution of chocolate/candy consumption between 1999 and 2001. The ORs for 19–25-year-olds (reference category: >25 years old) changed from 1.5 (95% CI 0.7–3.5) in 1999 to 0.2 (95% CI 0.2–0.5) in 2001. The OR for dental checkups at least once a year in students taking higher degree courses (reference category: lower degree/diploma students) changed from 1.7 (95% CI 1.2–2.5) in 1999 to 0.9 (95% CI 0.7–1.2) in 2001.
This paper documents the development of oral health-related behaviors and their sociodemographic distribution across time focusing on a non-occidental study population. Methodological strengths of the present study include the large sample size, the availability of comparable survey instruments, the sampling strategies and methods of data collection, and also, the diverse nature of the various oral health-related behaviors. A repeat cross-sectional survey, with the same target population and sampling frame, is the most appropriate and straightforward design for providing a series of survey estimates by which changes in a population can be monitored over periods of time . Trend studies of oral health-related behaviors, using a repeat cross-sectional design, have previously been reported mainly from the developed countries . This study design, although scientifically less rigorous than that of longitudinal studies, has been widely advocated by the United Nations, particularly in countries with limited resources . In the present study, data were gathered at different points in time from the same population, but not from the same individuals. Whereas a census survey was conducted in 2001, as intended, the analyzed data represent 64% of the intended sample in 1999. Lack of information about non-respondents precludes any conclusion about a possible selection bias, although the response rates seem to be high enough to ensure that the target population is reflected with a reasonable degree of accuracy. However, these estimates call for careful interpretation as the observed change may be due to differences between the samples rather than representing a true change in the population of MUCHS students.
The findings of the two surveys confirm that self-reported snacking of sugared food and drinks and dental attendance behavior were highest among females, higher degree students, and students of urban origin, thus corroborating previous studies of community populations in sub-Saharan African countries [4, 9, 10]. The present findings related to consumption of commercialized sugar products are in contrast to those reported from industrialized countries where the highest prevalence of sugar consumption has been observed among males and individuals of lower socioeconomic status . Previous research in both occidental and non-occidental populations has, however, demonstrated positive associations between reported self-care practices (e.g., going for dental checkups) and socioeconomic status, with the more affluent behaving more healthily than the less affluent [4, 18, 20]. In Tanzania, the cost-sharing policy implemented to ensure equity in access to modern health care services has not yet introduced user fees for services delivered by government-run oral health clinics . Since the government's health facilities are known to have shortages of drugs and other essential equipment, many seek care from private facilities where charges for services are high and there is no exemption system . Although university students have access to a free dental service at the MUCHS, we found that students of rural origin were less likely to visit dentists than were their urban counterparts. It is possible that students from a rural background and lower socioeconomic status were less likely to go for regular dental checkups because they could not afford to pay for the private care services. Consistent with other studies conducted in sub-Saharan Africa, more females than males reported abstinence from smoking across both survey years [4, 12]. One reason may be that the Tanzanian society still frowns upon tobacco use among women. This contrasts with the recent trends being reported from developed countries, where females are more frequent, and heavier, smokers than males [23, 24].
The two data sets from two surveys allowed us to examine changes that had taken place between 1999 and 2001. The results point to a general increase in the consumption of commercialized sugar products (e.g., Coca-Cola), whereas a commensurate decrease appears to have occurred with respect to the more traditional habit of taking sugar in coffee and tea. Interestingly, the regional differences in soft drink consumption, with urban students taking more soft drinks on a weekly basis than rural students, decreased markedly across the survey period. There was in fact a more pronounced increase in soft drink consumption among students raised in rural areas than among students from an urban background. Second-order effects from multiple logistic regression analyses revealed that the age differences in soft drink consumption changed from 1999 to 2001, with younger (19–25-year-old) students being the most frequent consumers in 1999 and older students (>25 years) being the most frequent consumers in 2001. Stratified analyses revealed this to be primarily a consequence of a pronounced increase in soft drink consumption among the older students. Contemporary consumption of commercialized sugar products is recognized to be closely associated with Western lifestyles, portrayed through the mass media and demonstrated in practice by acculturated segments of the Tanzanian population. Evidently, soft drink consumption is already established and is still on the increase among university students in Tanzania. The pronounced increase among students above 25 years old and students of rural origin may be interpreted as diffusion from higher to lower socioeconomic strata within this particular segment of the Tanzanian population . Contrary to what could be expected from an economic transitional point of view, the present analysis points to a general increase in reported total abstinence from tobacco use between 1999 to 2001.
The observed trend of an increase in oral hygiene measures and abstinence from tobacco among both sexes would suggest that the oral health education program in Tanzania's media is effective. This program targets mainly the urban population, of which university students constitute an important part. The finding that women are less likely than men to be informed by the mass media due to the Tanzanian sociocultural context  was not supported by the present study. Our finding and the observed decline in the social disparity between students of higher and lower degree with regard to dental checkup patterns between 1999 and 2001, corroborates the WHO target to achieve reduction in health inequalities between groups within countries by the year 2000 .
Since the present results rely on self-reported data, the rates of oral health behaviors may be biased through over- and underreporting due to social desirability and poor recall effects. Nevertheless, test-retest reliability of the oral health-related behaviors was examined in 1999 and found to be satisfactory . There is no reason to suspect changes in the accuracy of self-reported oral health behaviors across the survey period. Given this, the reported change, and lack of change, in students' oral health-related behaviors is likely to be reasonably accurate.
In summary, the present analysis suggests an increasing trend in the proportion of Tanzanian university students reporting abstinence from tobacco products, weekly consumption of commercialized sugar products, and implementation of oral hygiene measures from 1999 to 2001. Across the survey period, a decline was seen in the social disparity with regard to soft drink consumption (urban-rural) and dental checkup (educational level) patterns. In spite of some compatibility problems, this study represents the first opportunity to approach trends in a subnational population of Tanzanian adults. A third data collection will be necessary in 4–5 years' time to generate more conclusive trend data for use by health workers and policy makers in planning preventive oral health programs.
We owe our thanks to the students who took their time to participate in the comprehensive oral health surveys. We would also like to thank Dr. Lameck Mabelya, of the MUCHS, UDSM, Dar es Salaam, Tanzania, for his valuable guidance regarding data collection and cultural aspects of the survey instrument. Finally, we would like to thank Dr. Mathilda Mtaya and Dr. Jerome Kamwela, both from the UDSM, Dar es Salaam, for their contributions in the field. The financial support from the University of Bergen, Bergen, Norway, is gratefully acknowledged.
- Murray CJL, Lopez AD: Global mortality, disability and the contribution of risk factors: Global Burden of Disease Study. Lancet. 1997, 349: 1498-1504. 10.1016/S0140-6736(96)07492-2.View ArticlePubMedGoogle Scholar
- Mazengo MC, Simell O, Lukmanji Z, Shirma R, Karvetti RL: Food consumption in rural and urban Tanzania. Ada Tropica. 1997, 68: 313-326. 10.1016/S0001-706X(97)00113-7.View ArticleGoogle Scholar
- Mackay J: The tobacco problem: commercial profit versus health. The conflict of interests in developing countries. Prev Med. 1994, 23: 535-538. 10.1006/pmed.1994.1074.View ArticlePubMedGoogle Scholar
- Blay D, Åstrøm AN, Haugejorden O: Oral hygiene and sugar consumption among urban and rural adolescents in Ghana. Community Dent Oral Epidemiol. 2000, 28: 443-450. 10.1034/j.1600-0528.2000.028006443.x.View ArticlePubMedGoogle Scholar
- Åstrøm AN, Watiti J, Mwangosi EAT: Knowledge, beliefs and behaviour related to oral health among Tanzanian and Ugandan teacher trainees. Acta Odontol Scand. 2000, 58: 11-18. 10.1080/000163500429370.View ArticlePubMedGoogle Scholar
- Tapsoba H, Baumann M, Bakayoko L: Behaviours linked to dental health among 12-year old students in the Kadiogo province, Burkina Faso. Sante Publique. 1998, 10: 219-224.PubMedGoogle Scholar
- Kida IA, Åstrøm AN: Correlates of the intention to avoid sugared snacks among Tanzanian adolescents. Journal of Gender Culture and Health. 1998, 3: 171-182. 10.1023/A:1023241222619.View ArticleGoogle Scholar
- Åstrøm AN, Rise J: Socio-economic differences in patterns of health and oral health behaviour in 25-year-old Norwegians. Clin Oral Invest. 2001, 5: 122-128. 10.1007/s007840000102.View ArticleGoogle Scholar
- Miura H, Araki Y, Haraguchi K, Arai Y, Umenai T: Socioeconomic factors and dental caries on developing countries: a cross-national study. Soc Sci Med. 1997, 44: 269-272. 10.1016/S0277-9536(96)00167-0.View ArticlePubMedGoogle Scholar
- Kitange HM, Swai AB, Masuki G, Kilima PM, Albewrti KG, McLarty DG: Coronary heart disease risk factors in sub Saharan Africa: studies in Tanzanian adolescents. J Epidemiol and Comm Health. 1993, 47: 303-307.View ArticleGoogle Scholar
- Eide AH, Acuda SW: Adolescents' drug use in Zimbabwe comparing two recent studies. Centr Afr J Med. 1996, 42: 128-135.Google Scholar
- Adelekan ML, Ndom R, Obayan AI: Monitoring trends in substance use through a repeat cross-sectional survey in a Nigerian university. Drugs: Education, Prevention and Policy. 1996, 3: 239-247.Google Scholar
- Flisher AJ, Ziervogel CF, Chalton DO, Leger PH, Robertson BA: Risk-taking behavior of Cape Peninsula high-school students. 3: Cigarette-smoking. SAMJ. 1993, 83: 477-479.PubMedGoogle Scholar
- Mosha HJ, Scheutz F: Perceived need and use of oral health services among adolescents and adults in Tanzania. Community Dent Oral Epidemiol. 1993, 21: 129-132.View ArticlePubMedGoogle Scholar
- Rogers EM: Diffusion of innovations. 5th ed. New York, NY, The Free Press. 1995Google Scholar
- Ministry of Health, Tanzania: Policy implications of adults' morbidity and mortality. Dar es Salaam, Tanzania, Ministry of Health,. 1997Google Scholar
- Duncan GJ, Kalton G: Issues of design and analysis of surveys across time. Int Statist Rev. 1987, 55: 97-117.View ArticleGoogle Scholar
- Åstrøm AN, Samdal O: Time trends in oral health behaviors among Norwegian adolescents: 1985–1997. Acta Odontol Scan. 2001, 59: 193-200. 10.1080/00016350152509193.View ArticleGoogle Scholar
- United Nations Division of Narcotics: Manual on drug abuse assessment. Part two: use of population surveys. Document No. V.85-36588. Vienna, United Nations,. 1985Google Scholar
- Kuusela S, Honkala E, Kannas L, Tynjala J, Wold B: Oral hygiene habits of 11-year-old school children in 22 European countries and Canada in 1993/94. J Dent Res. 1997, 76: 1603-1609.View ArticleGoogle Scholar
- Ministry of Health, Tanzania: Implementation of health services user fees in Tanzania: an evaluation of progress and potential impact. Dar es Salaam, Tanzania, Ministry of Health,. 1996Google Scholar
- Masatu MC, Lugoe WL, Kvåle G, Klepp K-I: Health services utilisation among secondary school students in Arusha region, Tanzania. East Afr Med J. 2001, 78: 300-307.View ArticlePubMedGoogle Scholar
- National Council on Smoking and Health: Results from the Norwegian sample studies on smoking habit among students aged 13–15. Oslo, Norway, National Council on Smoking and Health,. 1991Google Scholar
- Kraft P, Svendsen T: Tobacco use among young adults in Norway, 1973–95: has the decrease levelled out?. Tobacco Control. 1997, 6: 27-32.View ArticlePubMedPubMed CentralGoogle Scholar
- Kapiga SH, Nachtigal G, Hunter DJ: Knowledge on AIDS among secondary school children in Bagamoyo and Dar esn Salaam, Tanzania. AIDS. 1991, 5: 325-328.View ArticlePubMedGoogle Scholar
- World Health Organization: Priority research for health for all. Copenhagen, Denmark, WHO Regional Office for Europe,. 1998Google Scholar
- Masalu JR, Åstrøm AN: Applicability of an abbreviated version of the Oral Impacts of Daily Performances (OIDP) scale for use among Tanzanian students. Community Dent Oral Epidemiol. 2001Google Scholar
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1472-6831/1/2/prepub
This article is published under license to BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL.