{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T21:39:36Z","timestamp":1790285976934,"version":"4.1.0"},"reference-count":41,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2023,9,14]],"date-time":"2023-09-14T00:00:00Z","timestamp":1694649600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2023,9,14]],"date-time":"2023-09-14T00:00:00Z","timestamp":1694649600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"name":"Danish Public Dentists\u2019 Organisation","award":["109290"],"award-info":[{"award-number":["109290"]}]},{"name":"Danish Public Dentists\u2019 Organisation","award":["109290"],"award-info":[{"award-number":["109290"]}]},{"name":"Royal Library, Copenhagen University Library"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["BMC Oral Health"],"abstract":"<jats:title>Abstract<\/jats:title><jats:sec>\n                <jats:title>Background<\/jats:title>\n                <jats:p>Few studies have examined the development of geographic and socioeconomic inequalities in caries over time or have simultaneously assessed individual-level socioeconomic position (SEP) and neighborhood-level factors as a multi-layered phenomenon influencing caries inequalities. This study examined (i) the trends in geographic inequalities in caries among adolescents in Denmark and (ii) how the association between SEP and caries has progressed over time, when accounting for individual and neighborhood-level confounding factors.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Methods<\/jats:title>\n                <jats:p>This nationwide repeated cross-sectional study included 15-year-olds in Denmark from 1995, 2003, and 2013 (<jats:italic>n<\/jats:italic>\u2009=\u2009149,808). The outcome was caries experience (measured by the decayed, missing, and filled tooth surfaces [DMFS] index). The exposure of interest was SEP, indicated by the previous year\u2019s parental education, occupational social class, and (equivalized) disposable household income. Covariates included individual-level factors (immigration status, country of origin, number of children and persons in the family, and household type) and neighborhood (residence municipality)-level factors (Gini index; proportion of unemployed, low-educated, and unmarried\/non-cohabiting individuals; proportion of single-parent households and households with overcrowding). Data sources included the Danish national dental and administrative social registers and Statistics Denmark\u2019s statistics database (StatBank). Data were analyzed using spatial and spatiotemporal modelling utilizing zero-inflated negative binomial regressions and integrated nested Laplace approximations for Bayesian parametric inference. Observed caries experience geo-maps of the Danish municipalities for 1995, 2003, and 2013 were created.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Results<\/jats:title>\n                <jats:p>Between 1995 and 2013, caries prevalence in the 15-year-olds declined sharply (1995, 71%; 2013, 45%). Caries experience declined in nearly all socioeconomic subgroups and municipalities. However, geographic inequalities persisted with higher caries levels largely concentrated in the relatively deprived areas of Denmark. Increasing relative socioeconomic inequalities in caries over time were observed with significant graded associations between SEP and caries despite adjustment for the various individual and neighborhood-level covariates and the effect of assessment year (e.g., 15-year-olds with parents having basic education had 1.91-fold [95% CI:\u00a01.86\u20131.95] higher caries experience than those having parents with high education).<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusions<\/jats:title>\n                <jats:p>Reducing these enduring inequalities will likely require additional resources and targeted supportive and preventive measures for adolescents from lower SEP backgrounds and those residing in municipalities with higher caries prevalence.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1186\/s12903-023-03373-5","type":"journal-article","created":{"date-parts":[[2023,9,14]],"date-time":"2023-09-14T01:01:53Z","timestamp":1694653313000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Development of geographic inequality in dental caries and its association with socioeconomic factors over an 18-year period in Denmark"],"prefix":"10.1186","volume":"23","author":[{"given":"Kaushik","family":"Sengupta","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kristine","family":"Bihrmann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lisa B\u00f8ge","family":"Christensen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laust Hvas","family":"Mortensen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ingelise","family":"Andersen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annette Kj\u00e6r","family":"Ersb\u00f8ll","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2023,9,14]]},"reference":[{"issue":"4","key":"3373_CR1","doi-asserted-by":"publisher","first-page":"392","DOI":"10.1177\/00220345211056247","volume":"101","author":"PYF Wen","year":"2022","unstructured":"Wen PYF, Chen MX, Zhong YJ, Dong QQ, Wong HM. Global burden and inequality of dental caries, 1990 to 2019. J Dent Res. 2022;101(4):392\u20139.","journal-title":"J Dent Res"},{"issue":"5","key":"3373_CR2","doi-asserted-by":"publisher","first-page":"458","DOI":"10.1111\/cdoe.12310","volume":"45","author":"K Sengupta","year":"2017","unstructured":"Sengupta K, Christensen LB, Mortensen LH, Skovgaard LT, Andersen I. Trends in socioeconomic inequalities in oral health among 15-year-old Danish adolescents during 1995\u20132013: a nationwide, register-based, repeated cross-sectional study. Community Dent Oral Epidemiol. 2017;45(5):458\u201368.","journal-title":"Community Dent Oral Epidemiol"},{"issue":"4","key":"3373_CR3","first-page":"448","volume":"6","author":"K Sengupta","year":"2020","unstructured":"Sengupta K, Ersb\u00f8ll AK, Christensen LB, Mortensen LH, Andersen I. Inequality, familial aggregation, and risk prediction of caries in siblings. JDR Clin Trans Res. 2020;6(4):448\u201357.","journal-title":"JDR Clin Trans Res"},{"issue":"12","key":"3373_CR4","doi-asserted-by":"publisher","first-page":"e038999","DOI":"10.1136\/bmjopen-2020-038999","volume":"10","author":"M Herke","year":"2020","unstructured":"Herke M, Moor I, Winter K, Hoffmann S, Spallek J, Hilger-Kolb J, Pischke C, Dragano N, Novelli A, Richter M. Role of contextual and compositional characteristics of schools for health inequalities in childhood and adolescence: protocol for a scoping review. BMJ Open. 2020;10(12):e038999.","journal-title":"BMJ Open"},{"key":"3373_CR5","doi-asserted-by":"publisher","first-page":"27106","DOI":"10.3402\/gha.v8.27106","volume":"8","author":"MC Arcaya","year":"2015","unstructured":"Arcaya MC, Arcaya AL, Subramanian SV. Inequalities in health: definitions, concepts, and theories. Glob Health Action. 2015;8:27106.","journal-title":"Glob Health Action"},{"issue":"1","key":"3373_CR6","doi-asserted-by":"publisher","first-page":"29","DOI":"10.1111\/j.1600-0528.2009.00505.x","volume":"38","author":"KR Ekstrand","year":"2010","unstructured":"Ekstrand KR, Christiansen ME, Qvist V, Ismail A. Factors associated with inter-municipality differences in dental caries experience among Danish adolescents. An ecological study. Community Dent Oral Epidemiol. 2010;38(1):29\u201342.","journal-title":"Community Dent Oral Epidemiol."},{"issue":"4","key":"3373_CR7","doi-asserted-by":"publisher","first-page":"291","DOI":"10.3109\/00016357.2015.1119306","volume":"74","author":"PE N\u00f8rrisgaard","year":"2016","unstructured":"N\u00f8rrisgaard PE, Qvist V, Ekstrand K. Prevalence, risk surfaces and inter-municipality variations in caries experience in Danish children and adolescents in 2012. Acta Odontol Scand. 2016;74(4):291\u20137.","journal-title":"Acta Odontol Scand"},{"key":"3373_CR8","doi-asserted-by":"publisher","first-page":"26","DOI":"10.1186\/1472-6831-11-26","volume":"11","author":"U Str\u00f6mberg","year":"2011","unstructured":"Str\u00f6mberg U, Magnusson K, Holm\u00e9n A, Twetman S. Geo-mapping of caries risk in children and adolescents - a novel approach for allocation of preventive care. BMC Oral Health. 2011;11:26.","journal-title":"BMC Oral Health"},{"key":"3373_CR9","volume-title":"Oral health surveys - basic methods","author":"World Health Organisation (WHO)","year":"2013","unstructured":"World Health Organisation (WHO). Oral health surveys - basic methods. 5th ed. Geneva, Switzerland: WHO Press; 2013.","edition":"5"},{"issue":"7 Suppl","key":"3373_CR10","doi-asserted-by":"publisher","first-page":"8","DOI":"10.1177\/1403494811409654","volume":"39","author":"LC Thygesen","year":"2011","unstructured":"Thygesen LC, Ersb\u00f8ll AK. Danish population-based registers for public health and health-related welfare research: introduction to the supplement. Scand J Public Health. 2011;39(7 Suppl):8\u201310.","journal-title":"Scand J Public Health"},{"issue":"7 Suppl","key":"3373_CR11","doi-asserted-by":"publisher","first-page":"91","DOI":"10.1177\/1403494810394715","volume":"39","author":"VM Jensen","year":"2011","unstructured":"Jensen VM, Rasmussen AW. Danish education registers. Scand J Public Health. 2011;39(7 Suppl):91\u20134.","journal-title":"Scand J Public Health"},{"issue":"7 Suppl","key":"3373_CR12","doi-asserted-by":"publisher","first-page":"103","DOI":"10.1177\/1403494811405098","volume":"39","author":"M Baadsgaard","year":"2011","unstructured":"Baadsgaard M, Quitzau J. Danish registers on personal income and transfer payments. Scand J Public Health. 2011;39(7 Suppl):103\u20135.","journal-title":"Scand J Public Health"},{"issue":"7 Suppl","key":"3373_CR13","doi-asserted-by":"publisher","first-page":"95","DOI":"10.1177\/1403494811408483","volume":"39","author":"F Petersson","year":"2011","unstructured":"Petersson F, Baadsgaard M, Thygesen LC. Danish registers on personal labour market affiliation. Scand J Public Health. 2011;39(7 Suppl):95\u20138.","journal-title":"Scand J Public Health"},{"key":"3373_CR14","unstructured":"Registry and variable summaries. Statistics Denmark. 2019. https:\/\/www.dst.dk\/extranet\/ForskningVariabellister\/FAIN%20-%20Husstande%20og%20familier.html. Accessed 9 Apr 2022."},{"issue":"7 Suppl","key":"3373_CR15","doi-asserted-by":"publisher","first-page":"22","DOI":"10.1177\/1403494810387965","volume":"39","author":"CB Pedersen","year":"2011","unstructured":"Pedersen CB. The Danish civil registration system. Scand J Public Health. 2011;39(7 Suppl):22\u20135.","journal-title":"Scand J Public Health"},{"key":"3373_CR16","unstructured":"Statbank. Statistics Denmark. 2021. https:\/\/www.statbank.dk\/statbank5a\/default.asp?w=1280. Accessed 9 Apr 2022."},{"key":"3373_CR17","unstructured":"United Nations Educational, Scientific and Cultural Organisation (UNESCO). International Standard Classification of Education - ISCED 2011. UNESCO Institute for Statistics. 2011. http:\/\/uis.unesco.org\/sites\/default\/files\/documents\/international-standard-classification-of-education-isced-2011-en.pdf. Accessed 9 Apr 2022."},{"key":"3373_CR18","unstructured":"FAMAEKVIVADISP (equivalised disposable income for the family). Statistics Denmark. 2021. https:\/\/www.dst.dk\/da\/Statistik\/dokumentation\/Times\/familieindkomst\/famaekvivadisp. Accessed 9 Apr 2022."},{"issue":"1","key":"3373_CR19","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1007\/BF00116466","volume":"43","author":"J Besag","year":"1991","unstructured":"Besag J, York J, Mollie A. Bayesian image restoration, with application in spatial statistics with discussion. Ann Inst Stat Math. 1991;43(1):1\u201320.","journal-title":"Ann Inst Stat Math"},{"issue":"2","key":"3373_CR20","doi-asserted-by":"publisher","first-page":"284","DOI":"10.1111\/j.1467-8306.2004.09402005.x","volume":"94","author":"HJ Miller","year":"2004","unstructured":"Miller HJ. Tobler\u2019s first law and spatial analysis. Ann Assoc Am Geogr. 2004;94(2):284\u20139.","journal-title":"Ann Assoc Am Geogr"},{"key":"3373_CR21","doi-asserted-by":"publisher","first-page":"39","DOI":"10.1016\/j.sste.2013.07.003","volume":"7","author":"M Blangiardo","year":"2013","unstructured":"Blangiardo M, Cameletti M, Baio G, Rue H. Spatial and spatio-temporal models with R-INLA. Spat Spatiotemporal Epidemiol. 2013;7:39\u201355.","journal-title":"Spat Spatiotemporal Epidemiol"},{"key":"3373_CR22","unstructured":"Rue H, Martino S, Chopin N. R-INLA package. 2021. http:\/\/www.r-inla.org\/. Accessed 9 Apr 2022."},{"key":"3373_CR23","volume-title":"The municipal dental care (Den kommunale tandpleje)","author":"Danish Health Authority","year":"2018","unstructured":"Danish Health Authority. The municipal dental care (Den kommunale tandpleje). Copenhagen: Denmark; 2018."},{"key":"3373_CR24","unstructured":"Ministry of Economic and Business Affairs. Denmark in balance in a global world (Danmark i balance i en global verden). Albertslund, Denmark; 2010. https:\/\/www.regeringen.dk\/aktuelt\/tidligere-publikationer\/danmark-i-balance-i-en-global-verden\/ (in Danish). Accessed 9 Apr 2022."},{"issue":"8","key":"3373_CR25","doi-asserted-by":"publisher","first-page":"551","DOI":"10.1007\/s10654-013-9873-0","volume":"29","author":"LC Thygesen","year":"2014","unstructured":"Thygesen LC, Ersb\u00f8ll AK. When the entire population is the sample: strengths and limitations in register-based epidemiology. Eur J Epidemiol. 2014;29(8):551\u20138.","journal-title":"Eur J Epidemiol"},{"key":"3373_CR26","first-page":"23","volume-title":"Methods in social epidemiology","author":"M Oakes","year":"2017","unstructured":"Oakes M, Andrade K. The measurement of socioeconomic status. In: Oakes M, Kaufman J, editors. Methods in social epidemiology. 2nd ed. San Francisco, CA: Jossey-Bass & Pfeiffer Imprint, Wiley; 2017. p. 23\u201342.","edition":"2"},{"key":"3373_CR27","first-page":"99","volume-title":"Causal inference: what if","author":"MA Hern\u00e1n","year":"2020","unstructured":"Hern\u00e1n MA, Robins JM. Selection bias. In: Hern\u00e1n MA, Robins JM, editors. Causal inference: what if. 1st ed. Boca Raton, FL: Chapman & Hall\/CRC; 2020. p. 99\u2013112.","edition":"1"},{"issue":"12","key":"3373_CR28","doi-asserted-by":"publisher","first-page":"1080","DOI":"10.1136\/jech.2006.052910","volume":"61","author":"JI Virtanen","year":"2007","unstructured":"Virtanen JI, Berntsson LT, Lahelma E, K\u00f6hler L, Murtomaa H. Children\u2019s use of dental services in the five Nordic countries. J Epidemiol Community Health. 2007;61(12):1080\u20135.","journal-title":"J Epidemiol Community Health"},{"key":"3373_CR29","doi-asserted-by":"publisher","first-page":"9","DOI":"10.1186\/1472-6831-12-9","volume":"12","author":"U Str\u00f6mberg","year":"2012","unstructured":"Str\u00f6mberg U, Holmn A, Magnusson K, Twetman S. Geo-mapping of time trends in childhood caries risk\u2013a method for assessment of preventive care. BMC Oral Health. 2012;12:9.","journal-title":"BMC Oral Health"},{"issue":"4","key":"3373_CR30","doi-asserted-by":"publisher","first-page":"685","DOI":"10.1016\/j.jhealeco.2011.04.004","volume":"30","author":"G Erreygers","year":"2011","unstructured":"Erreygers G, Van Ourti T. Measuring socioeconomic inequality in health, health care and health financing by means of rank-dependent indices: a recipe for good practice. J Health Econ. 2011;30(4):685\u201394.","journal-title":"J Health Econ"},{"issue":"1","key":"3373_CR31","doi-asserted-by":"publisher","first-page":"3","DOI":"10.1111\/j.1600-0528.1973.tb01055.x","volume":"1","author":"S Helm","year":"1973","unstructured":"Helm S. Recording system for the Danish child dental health services. Community Dent Oral Epidemiol. 1973;1(1):3\u20138.","journal-title":"Community Dent Oral Epidemiol"},{"issue":"1","key":"3373_CR32","doi-asserted-by":"publisher","first-page":"30","DOI":"10.1111\/j.1752-7325.2006.tb02548.x","volume":"66","author":"M Tellez","year":"2006","unstructured":"Tellez M, Sohn W, Burt BA, Ismail AI. Assessment of the relationship between neighborhood characteristics and dental caries severity among low-income African-Americans: a multilevel approach. J Public Health Dent. 2006;66(1):30\u20136.","journal-title":"J Public Health Dent"},{"issue":"2","key":"3373_CR33","doi-asserted-by":"publisher","first-page":"130","DOI":"10.1159\/000069021","volume":"37","author":"KR Ekstrand","year":"2003","unstructured":"Ekstrand KR, Christiansen ME, Qvist V. Influence of different variables on the inter-municipality variation in caries experience in Danish adolescents. Caries Res. 2003;37(2):130\u201341.","journal-title":"Caries Res"},{"issue":"11","key":"3373_CR34","doi-asserted-by":"publisher","first-page":"2020","DOI":"10.1016\/j.socscimed.2010.09.006","volume":"71","author":"KA Levin","year":"2010","unstructured":"Levin KA, Davies CA, Douglas GV, Pitts NB. Urban-rural differences in dental caries of 5-year-old children in Scotland. Soc Sci Med. 2010;71(11):2020\u20137.","journal-title":"Soc Sci Med"},{"issue":"6","key":"3373_CR35","doi-asserted-by":"publisher","first-page":"542","DOI":"10.1111\/j.1467-842X.2004.tb00044.x","volume":"28","author":"DS Brennan","year":"2004","unstructured":"Brennan DS, Spencer AJ. Changes in caries experience among Australian public dental patients between 1995\/96 and 2001\/02. Aust N Z J Public Health. 2004;28(6):542\u20138.","journal-title":"Aust N Z J Public Health"},{"issue":"4","key":"3373_CR36","first-page":"225","volume":"24","author":"U Krustrup","year":"2007","unstructured":"Krustrup U, Petersen PE. Dental caries prevalence among adults in Denmark\u2013the impact of socio-demographic factors and use of oral health services. Community Dent Health. 2007;24(4):225\u201332.","journal-title":"Community Dent Health"},{"issue":"2","key":"3373_CR37","doi-asserted-by":"publisher","first-page":"153","DOI":"10.1111\/jphd.12039","volume":"74","author":"C Funieru","year":"2014","unstructured":"Funieru C, Twetman S, Funieru E, Dumitrache AM, Sfeatcu RI, Baicus C. Caries experience in schoolchildren in Bucharest, Romania: the PAROGIM study. J Public Health Dent. 2014;74(2):153\u20138.","journal-title":"J Public Health Dent"},{"issue":"12","key":"3373_CR38","doi-asserted-by":"publisher","first-page":"e006391","DOI":"10.1136\/bmjopen-2014-006391","volume":"4","author":"MR Mathur","year":"2014","unstructured":"Mathur MR, Tsakos G, Millett C, Arora M, Watt R. Socioeconomic inequalities in dental caries and their determinants in adolescents in New Delhi, India. BMJ Open. 2014;4(12):e006391.","journal-title":"BMJ Open"},{"issue":"2","key":"3373_CR39","doi-asserted-by":"publisher","first-page":"105","DOI":"10.1159\/000116874","volume":"42","author":"I Perera","year":"2008","unstructured":"Perera I, Ekanayake L. Social gradient in dental caries among adolescents in Sri Lanka. Caries Res. 2008;42(2):105\u201311.","journal-title":"Caries Res"},{"issue":"3","key":"3373_CR40","doi-asserted-by":"publisher","first-page":"187","DOI":"10.1111\/jphd.12261","volume":"78","author":"GD Slade","year":"2018","unstructured":"Slade GD, Sanders AE. Two decades of persisting income-disparities in dental caries among U.S. children and adolescents. J Public Health Dent. 2018;78(3):187\u201391.","journal-title":"J Public Health Dent"},{"issue":"4","key":"3373_CR41","first-page":"85","volume":"20","author":"R Pampalon","year":"2009","unstructured":"Pampalon R, Hamel D, Gamache P. A comparison of individual and area-based socio-economic data for monitoring social inequalities in health. Health Rep. 2009;20(4):85\u201394.","journal-title":"Health Rep"}],"container-title":["BMC Oral Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12903-023-03373-5.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1186\/s12903-023-03373-5\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12903-023-03373-5.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,11,22]],"date-time":"2023-11-22T00:04:13Z","timestamp":1700611453000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmcoralhealth.biomedcentral.com\/articles\/10.1186\/s12903-023-03373-5"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,9,14]]},"references-count":41,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2023,12]]}},"alternative-id":["3373"],"URL":"https:\/\/doi.org\/10.1186\/s12903-023-03373-5","relation":{},"ISSN":["1472-6831"],"issn-type":[{"value":"1472-6831","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,9,14]]},"assertion":[{"value":"29 October 2022","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"30 August 2023","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"14 September 2023","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"This was a register-based study using anonymized data. According to Danish law (The Act on Processing of Personal Data: Act No. 429 of May 31, 2000 with amendments), approval from an ethical committee and informed consent from the study subjects are not required when performing register-based studies [Thygesen et al. 2011*]. Register-based studies should, however, be approved by The Danish Data Protection Agency. Accordingly, approval for the study was obtained from the Danish Data Protection Agency (approval no. j-no.\u00a02015\u201341-3790).The study did not involve contacts with participants or human material. We confirm that all methods were carried out in accordance with relevant guidelines and regulations outlined in the Declaration of Helsinki.*Thygesen LC, Daasnes C, Thaulow I, Br\u00f8nnum-Hansen H. Introduction to Danish (nationwide) registers on health and social issues: structure, access, legislation, and archiving. Scand J Public Health. 2011;39(Suppl 7):12\u20136.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Not applicable.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare no competing interests.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"662"}}