Income-related inequalities in preventive and curative dental care use among working-age Japanese adults in urban areas: a cross-sectional study

BMC Oral Health

Hideki Hashimoto³  Takayoshi Ohkubo²  Jun Aida¹  Keiko Murakami³ 

[1] Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan;Department of Hygiene and Public Health, School of Medicine, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan;Department of Health and Social Behavior, School of Public Health, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

关键词: Japan;    Inequality;    Income;    Dental insurance;    Dental care;   

Others  :  1091764
DOI  :  10.1186/1472-6831-14-117

 received in 2014-04-30, accepted in 2014-09-15,  发布年份 2014

【 摘 要 】

Background

Preventive dental care use remains relatively low in Japan, especially among working-age adults. Universal health insurance in Japan covers curative dental care with an out-of-pocket payment limit, though its coverage of preventive dental care is limited. The aim of this study was to test the hypothesis that income inequality in dental care use is found in preventive, but not curative dental care among working-age Japanese adults.

Methods

A cross-sectional survey was conducted using a computer-assisted, self-administered format for community residents aged 25–50 years. In all, 4357 residents agreed to participate and complete the questionnaire (valid response rate: 31.3%). Preventive dental care use was measured according to whether the participant had visited a dentist or a dental hygienist during the past year for dental scaling or fluoride or orthodontic treatments. Curative dental care use was assessed by dental visits for other reasons. The main explanatory variable was equivalent household income. Logistic regression analyses with linear trend tests were conducted to determine whether there were significant income-related gradients with curative or preventive dental care use.

Results

Among the respondents, 40.0% of men and 41.5% of women had used curative dental care in the past year; 24.1% of men and 34.1% of women had used preventive care. We found no significant income-related gradients of curative dental care among either men or women (p = 0.234 and p = 0.270, respectively). Significant income-related gradients of preventive care were observed among both men and women (p < 0.001 and p = 0.003, respectively). Among women, however, income-related differences were no longer significant (p = 0.126) after adjusting for education and other covariates. Compared with men with the lowest income, the highest-income group had a 1.79-fold significantly higher probability for using preventive dental care.

Conclusions

The prevalence of preventive dental care use was lower than that of curative care. The results showed income-related inequality in preventive dental care use among men, though there were no significant income-related gradients of curative dental care use among either men or women. Educational attainment had a positive association with preventive dental care use only among women.

【 授权许可】

   
2014 Murakami et al.; licensee BioMed Central Ltd.

【 参考文献 】

• [1]Murata C, Yamada T, Chen CC, Ojima T, Hirai H, Kondo K: Barriers to health care among the elderly in Japan. Int J Environ Res Public Health 2010, 7:1330-1341.
• [2]Grytten J, Holst D, Skau I: Demand for and utilization of dental services according to household income in the adult population in Norway. Community Dent Oral Epidemiol 2012, 40:297-305.
• [3]Lu JF, Leung GM, Kwon S, Tin KY, van Doorslaer E, O’Donnell O: Horizontal equity in health care utilization evidence from three high-income Asian economies. Soc Sci Med 2007, 64:199-212.
• [4]van Doorslaer E, Masseria C: Income-related inequality in the use of medical care in 21 OECD countries. In Towards High-Performing Health Systems: Policy Studies. Edited by Organisation for Economic Co-operation and Development. Paris: OECD Publishing; 2004:109-165.
• [5]Maharani DA, Rahardjo A: Is the utilisation of dental care based on need or socioeconomic status? A study of dental care in Indonesia from 1999 to 2009. Int Dent J 2012, 62:90-94.
• [6]Somkotra T, Detsomboonrat P: Is there equity in oral healthcare utilization: experience after achieving Universal Coverage. Community Dent Oral Epidemiol 2009, 37:85-96.
• [7]Haugejorden O, Klock KS, Astrom AN, Skaret E, Trovik TA: Socio-economic inequality in the self-reported number of natural teeth among Norwegian adults – an analytical study. Community Dent Oral Epidemiol 2008, 36:269-278.
• [8]Wamala S, Merlo J, Bostrom G: Inequity in access to dental care services explains current socioeconomic disparities in oral health: the Swedish National Surveys of Public Health 2004–2005. J Epidemiol Community Health 2006, 60:1027-1033.
• [9]Hjern A, Grindefjord M, Sundberg H, Rosen M: Social inequality in oral health and use of dental care in Sweden. Community Dent Oral Epidemiol 2001, 29:167-174.
• [10]Ikegami N, Yoo BK, Hashimoto H, Matsumoto M, Ogata H, Babazono A, Watanabe R, Shibuya K, Yang BM, Reich MR, Kobayashi Y: Japanese universal health coverage: evolution, achievements, and challenges. Lancet 2011, 378:1106-1115.
• [11]Shika hoken kenkyukai: Zenka jitsurei ni yoru shakai hoken shika shinryo, 2013. Tokyo; 2013. in Japanese
• [12]Sintonen H, Linnosmaa I: Economics of dental services. In Handbook of Health Economics, Volume 1B. Edited by Culyer AJ, Newhouse JP. Amsterdam: Elsevier; 2000:1251-1296.
• [13]Ministry of Health, Labour and Welfare: The National Health and Nutrition Survey in Japan, 2009. Tokyo; 2012. in Japanese
• [14]Moriya S, Ando Y, Miura H: Trends and prospects of oral health conditions among Japanese: the achievement of 8020. J Natl Inst Public Health 2011, 60:379-386. in Japanese, only abstract in English
• [15]Kiyak HA, Reichmuth M: Barriers to and enablers of older adults’ use of dental services. J Dent Educ 2005, 69:975-986.
• [16]Lorenc T, Petticrew M, Welch V, Tugwell P: What types of interventions generate inequalities? Evidence from systematic reviews. J Epidemiol Community Health 2013, 67:190-193.
• [17]Takada M, Kondo N, Hashimoto H, for the J-SHINE Data Management Committee: Japanese Study on Stratification, Health, Income, and Neighborhood: study protocol and profiles of participants. J Epidemiol 2014, 24:334-344.
• [18]Hagenaars AJM, de Vos K, Zaidi MA: Poverty statistics in the late 1980s: research based on micro-data. Luxembourg: Office for Official Publications of the European Communities; 1994.
• [19]Jones JA, Spiro A 3rd, Miller DR, Garcia RI, Kressin NR: Need for dental care in older veterans: assessment of patient-based measures. J Am Geriatr Soc 2002, 50:163-168.
• [20]Jones JA, Kressin NR, Miller DR, Orner MB, Garcia RI, Spiro A 3rd: Comparison of patient-based oral health outcome measures. Qual Life Res 2004, 13:975-985.
• [21]Hanibuchi T, Aida J, Nakade M, Hirai H, Kondo K: Geographical accessibility to dental care in the Japanese elderly. Community Dent Health 2011, 28:128-135.
• [22]Grignon M, Hurley J, Wang L, Allin S: Inequity in a market-based health system: evidence from Canada's dental sector. Health Policy 2010, 98:81-90.
• [23]Listl S: Income-related inequalities in dental service utilization by Europeans aged 50+. J Dent Res 2011, 90:717-723.
• [24]Krieger N, Chen JT, Selby JV: Comparing individual-based and household-based measures of social class to assess class inequalities in women's health: a methodological study of 684 US women. J Epidemiol Community Health 1999, 53:612-623.
• [25]Honjo K, Iso H, Iwata M, Cable N, Inoue M, Sawada N, Tsugane S, JPHC Study Group: Effectiveness of the combined approach for assessing social gradients in stroke risk among married women in Japan. J Epidemiol 2012, 22:324-330.
• [26]Sakurai K, Kawakami N, Yamaoka K, Ishikawa H, Hashimoto H: The impact of subjective and objective social status on psychological distress among men and women in Japan. Soc Sci Med 2010, 70:1832-1839.
• [27]Green CA, Pope CR: Gender, psychosocial factors and the use of medical services: a longitudinal analysis. Soc Sci Med 1999, 48:1363-1372.
• [28]Nguyen L, Hakkinen U: Income-related inequality in the use of dental services in Finland. Appl Health Econ Health Policy 2004, 3:251-262.
• [29]Moeller JF, Chen H, Manski RJ: Investing in preventive dental care for the Medicare population: a preliminary analysis. Am J Public Health 2010, 100:2262-2269.
• [30]Lowe C, Blinkhorn AS, Worthington HV, Craven R: Testing the effect of including oral health in general health checks for elderly patients in medical practice - a randomized controlled trial. Community Dent Oral Epidemiol 2007, 35:12-17.
• [31]Sato M: Present and future of economic evaluation in the field of dentistry. J Health Care Soc 2002, 12:117-134. in Japanese, only abstract in English
• [32]Tolonen H, Dobson A, Kulathinal S, WHO MONICA Project: Effect on trend estimates of the difference between survey respondents and non-respondents: results from 27 populations in the WHO MONICA Project. Eur J Epidemiol 2005, 20:887-898.
• [33]Laaksonen M, Aittomäki A, Lallukka T, Rahkonen O, Saastamoinen P, Silventoinen K, Lahelma E: Register-based study among employees showed small nonparticipation bias in health surveys and check-ups. J Clin Epidemiol 2008, 61:900-906.
• [34]Toyokawa S, Kobayashi Y: Increasing supply of dentists induces their geographic diffusion in contrast with physicians in Japan. Soc Sci Med 2010, 71:2014-2019.
• [35]Galobardes B, Shaw M, Lawlor DA, Lynch JW, Davey SG: Indicators of socioeconomic position (part 1). J Epidemiol Community Health 2006, 60:7-12.
• [36]Ministry of Health, Labour and Welfare: The Comprehensive Survey of the Living Conditions of People on Health and Welfare in Japan, 2010. Tokyo; 2012. (in Japanese)