The Oslo Health Study: The impact of self-selection in a large, population-based survey

International Journal for Equity in Health

Dag Thelle¹  Espen Bjertness²  Randi Selmer³  Anne Johanne Søgaard³ 

[1]Akershus University Hospital, Faculty of Medicine, University of Oslo, Norway

[2]Institute of General Practice and Community Medicine, Faculty of Medicine, University of Oslo, Norway

[3]Norwegian Institute of Public Health, Oslo, Norway

关键词: disability benefit.;    response rate;    ethnicity;    bias;    self-selection;    response bias;    non-response;    health surveys;    equity;    Epidemiological studies;   

Others  :  1147862
DOI  :  10.1186/1475-9276-3-3

 received in 2003-09-26, accepted in 2004-05-06,  发布年份 2004

【 摘 要 】

Background

Research on health equity which mainly utilises population-based surveys, may be hampered by serious selection bias due to a considerable number of invitees declining to participate. Sufficient information from all the non-responders is rarely available to quantify this bias. Predictors of attendance, magnitude and direction of non-response bias in prevalence estimates and association measures, are investigated based on information from all 40 888 invitees to the Oslo Health Study.

Methods

The analyses were based on linkage between public registers in Statistics Norway and the Oslo Health Study, a population-based survey conducted in 2000/2001 inviting all citizens aged 30, 40, 45, 59–60 and 75–76 years. Attendance was 46%. Weighted analyses, logistic regression and sensitivity analyses are performed to evaluate possible selection bias.

Results

The response rate was positively associated with age, educational attendance, total income, female gender, married, born in a Western county, living in the outer city residential regions and not receiving disability benefit. However, self-rated health, smoking, BMI and mental health (HCSL) in the attendees differed only slightly from estimated prevalence values in the target population when weighted by the inverse of the probability of attendance.

Observed values differed only moderately provided that the non-attending individuals differed from those attending by no more than 50%. Even though persons receiving disability benefit had lower attendance, the associations between disability and education, residential region and marital status were found to be unbiased. The association between country of birth and disability benefit was somewhat more evident among attendees.

Conclusions

Self-selection according to sociodemographic variables had little impact on prevalence estimates. As indicated by disability benefit, unhealthy persons attended to a lesser degree than healthy individuals, but social inequality in health by different sociodemographic variables seemed unbiased. If anything we would expect an overestimation of the odds ratio of chronic disease among persons born in non-western countries.

【 授权许可】

   
2004 Søgaard et al; licensee 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.

【 参考文献 】

• [1]Townsend P, Davidson N: The Black report. Harmondsworth: Pelican Books; 1982.
• [2]Macintyre S: The Black Report and beyond: what are the issues? Soc Sci Med 1997, 44:723-45.
• [3]Lynch JW, Smith GD, Kaplan GA, House JS: Income inequality and mortality: importance to health of individual income, psychosocial environment, or material conditions. BMJ 2000, 320:1200-4.
• [4]Marmot M, Wilkinson RG: Psychosocial and material pathways in the relation between income and health: a response to Lynch et al. BMJ 2001, 322:1233-6.
• [5]Mackenbach JP, Kunst AE, Cavelaars AE, Groenhof F, Geurts JJ, and the EU Working Group on Socioeconomic Inequalities in Health: Socioeconomic inequalities in morbidity and mortality in western Europe. Lancet 1997, 349:1655-9.
• [6]Rognerud MA, Kruger O, Gjertsen F, Thelle DS: Strong regional links between socio-economic background factors and disability and mortality in Oslo, Norway. Eur J Epidemiol 1998, 14:457-63.
• [7]Wilhelmsen L, Tibblin G, Werko L: A primary preventive study of Gothenburg, Sweden. Prev Med 1972, 1:153-60.
• [8]Jacobsen BK, Thelle DS: The Tromso Heart Study: responders and non-responders to a health questionnaire, do they differ? Scand J Soc Med 1988, 16:101-4.
• [9]Osler M, Schroll M: Differences between participants and non-participants in a population study on nutrition and health in the elderly. Eur J Clin Nutr 1992, 46:289-95.
• [10]Bostrom G, Hallqvist J, Haglund BJ, Romelsjo A, Svanstrom L, Diderichsen F: Socioeconomic differences in smoking in an urban Swedish population. The bias introduced by non-participation in a mailed questionnaire. Scand J Soc Med 1993, 21:77-82.
• [11]Launer LJ, Wind AW, Deeg DJ: Nonresponse pattern and bias in a community-based cross-sectional study of cognitive functioning among the elderly. Am J Epidemiol 1994, 139:803-12.
• [12]Jackson R, Chambless LE, Yang K, Byrne T, Watson R, Folsom A, Shahar E, Kalsbeek W, for the Atherosclerosis Risk in Communities (ARIC) Study Investigators: Differences between respondents and nonrespondents in a multicenter community-based study vary by gender and ethnicity. J Clin Epidemiol 1996, 49:1441-46.
• [13]Belsby L, Vedø A: Non-response analysis of the Norwegian Health Survey 1995. [Frafallsanalyse av Helseundersøkelsen 1995]. Notater 3/98. Oslo: Statistics Norway; 1998. (in Norwegian)
• [14]Hoeymans N, Feskens EJ, Van Den Bos GA, Kromhout D: Non-response bias in a study of cardiovascular diseases, functional status and self-rated health among elderly men. Age Ageing 1998, 27:35-40.
• [15]Reijneveld SA, Stronks K: The impact of response bias on estimates of health care utilization in a metropolitan area: the use of administrative data. Int J Epidemiol 1999, 28:1134-40.
• [16]Berglund G, Nilsson P, Eriksson KF, Nilsson JA, Hedblad B, Kristenson H, Lindgarde F: Long-term outcome of the Malmo preventive project: mortality and cardiovascular morbidity. J Intern Med 2000, 247:19-29.
• [17]Korkeila K, Suominen S, Ahvenainen J, Ojanlatva A, Rautava P, Helenius H, Koskenvuo M: Non-response and related factors in a nation-wide health survey. Eur J Epidemiol 2001, 17:991-9.
• [18]van Loon AJ, Tijhuis M, Picavet HS, Surtees PG, Ormel J: Survey non-response in the Netherlands. Effects on prevalence estimates and associations. Ann Epidemiol 2003, 13:105-10.
• [19]van den Brandt PA, Goldbohm RA, van 't Veer P, Volovics A, Hermus RJ, Sturmans F: A large-scale prospective cohort study on diet and cancer in The Netherlands. J Clin Epidemiol 1990, 43:285-95.
• [20]Livingston PM, McCarty CA, Taylor HR: Visual impairment and socioeconomic factors. Br J Ophthalmol 1997, 81:574-7.
• [21]der Wiel AB, van Exel E, de Craen AJ, Gussekloo J, Lagaay AM, Knook DL, Westendorp RG: A high response is not essential to prevent selection bias: results from the Leiden 85-plus study. J Clin Epidemiol 2002, 55:1119-25.
• [22]Bergstrand R, Vedin A, Wilhelmsson C, Wilhelmsen L: Bias due to non-participation and heterogenous sub-groups in population surveys. J Chronic Dis 1983, 36:725-8.
• [23]Wilhelmsen L, Ljungberg S, Wedel H, Werko L: A comparison between participants and non-participants in a primary preventive trial. J Chronic Dis 1976, 29:331-9.
• [24]Norwegian Institute of Public Health. The Oslo Health Study [http://www.fhi.no/tema/helseundersokelse/oslo/index.html] webcite
• [25]The Oslo Health Study: Protocol. Oslo: Norwegian Institute of Public Health; 2002. (in Norwegian)
• [26]Statistics Norway [http://www.ssb.no/english/subjects/05/01/inntind_en/about.html] webcite
• [27]Strand BH, Dalgard OS, Tambs K, Rognerud M: Measuring the mental health status of the Norwegian population: a comparison of the instruments SCL-25 SCL-10, SCL-5 and MHI-5 (SF-36). Nordic J Pschychiatry 2003, 57:113-8.
• [28]Derogatis LR, Lipman RS, Rickels K, Uhlenhuth EH, Covi L: The Hopkins Symptom Checklist (HSCL): a self-report symptom inventory. Behav Sci 1974, 19:1-15.
• [29]Hara M, Sasaki S, Sobue T, Yamamoto S, Tsugane S: Comparison of cause-specific mortality between respondents and nonrespondents in a population-based prospective study: ten-year follow-up of JPHC Study Cohort I. Japan Public Health Center. J Clin Epidemiol 2002, 55:150-6.
• [30]Bjartveit K, Foss OP, Gjervig T: The cardiovascular disease study in Norwegian counties. Results from first screening. Acta Med Scand Suppl 1983, 675:1-184.
• [31]Lund-Larsen PG: ECG in health and disease. ECG findings in relation to CHD risk factors, constitutional variables and 16-year mortality in 2990 asymptomatic Oslo men aged 40–49 years in 1972. PhD thesis. ISM-skriftserie, nr. 30. University of Tromsø, Institute of Community Medicine; 1994.
• [32]Bergdahl M, Ekman S, Lindberg A, Lundquist P, Rennermalm M: The non-response monitor no. 6. [Bortfallsbarometern nr 6] (R&D Report nr 13). Stockholm: Statistics Sweden; 1991. (in Swedish)
• [33]Smith T: Changes in non-response on the US general social surveys, 1975–94. Presented at the Fifth International Workshop on Household Survey Non-Response, Ottawa, Ontario, CanadaSeptember 26–28 1994
• [34]Belsby L: The non-response problem increases. [Frafallsproblemet øker]. Samfunnsspeilet 1997, 2:10-13. (in Norwegian)
• [35]Bjartveit K, Wøien G: Cardiovascular disease risk factors in Norway. Results from surveys in 18 countries. Oslo: National Health Screening Service; 1997.
• [36]Helakorpi S, Uutela A, Prättälä R, Puska P: Health behaviour among Finnish adult population, B19/1999. Helsinki: Publications of the National Public Health Institute; 1999. (in Finnish, English abstract)
• [37]O'Neill TW, Marsden D, Silman AJ: Differences in the characteristics of responders and non-responders in a prevalence survey of vertebral osteoporosis. European Vertebral Osteoporosis Study Group. Osteoporos Int 1995, 5:327-34.
• [38]Lund E, Gram IT: Response rate according to title and length of questionnaire. Scand J Soc Med 1998, 26:154-60.
• [39]Iglesias C, Torgerson D: Does length of questionnaire matter? A randomised trial of response rates to a mailed questionnaire. J Health Serv Res Policy 2000, 5:219-221.
• [40]Keeter S, Miller C, Kohut A, Groves RM, Presser S: Consequences of reducing nonresponse in a national telephone survey. Public Opin Q 2000, 64:125-48.
• [41]Curtin R, Presser S, Singer E: The effects of response rate changes on the index of consumer sentiment. Public Opin Q 2000, 64:413-28.
• [42]Criqui MH, Barrett-Connor E, Austin M: Differences between respondents and non-respondents in a population-based cardiovascular disease study. Am J Epidemiol 1978, 108:367-72.
• [43]Selmer S, Søgaard R, Bjertness E, Thelle D: The Oslo Health Study. Reminding the non-responders – effects on prevalence estimates. Nor J Epidemiol 2003, 13:89-94.
• [44]Kleinbaum DG, Kupper LL, Morgenstern H: Selection Bias. In Epidemiologic Research. Edited by Kleinbaum DG, Kupper LL, Morgenstern H. New York: Van Nostrand Reinhold Company Inc; 1982:194-219.
• [45]Heilbrun LK, Nomura A, Stemmermann GN: The effects of nonresponse in a prospective study of cancer. Am J Epidemiol 1982, 116:353-63.
• [46]Benfante R, Reed D, MacLean C, Kagan A: Response bias in the Honolulu Heart Program. Am J Epidemiol 1989, 130:1088-100.
• [47]Vernon SW, Roberts RE, Lee ES: Ethnic status and participation in longitudinal health surveys. Am J Epidemiol 1984, 119:99-113.
• [48]Austin MA, Criqui MH, Barrett-Connor E, Holdbrook MJ: The effect of response bias on the odds ratio. Am J Epidemiol 1981, 114:137-43.
• [49]Eagan TM, Eide GE, Gulsvik A, Bakke PS: Nonresponse in a community cohort study: predictors and consequences for exposure-disease associations. J Clin Epidemiol 2002, 55:775-81.
• [50]Rothman KJ, Greenland S: Precision and validity in epidemiological studies. In Modern Epidemiology. 2nd edition. Edited by Rothman KJ, Greenland S. Philadelphia: Lippincott-Raven; 1998:115-34.
• [51]The Steering Committee of the Physicians' Health Study Research Group: Preliminary Report: Findings from the aspirin component of the ongoing Physicians' Health Study. Engl J Med 1988, 318:262-4.
• [52]Guallar E, Hennekens CH, Sacks FM, Willett WC, Stampfer MJ: A prospective study of plasma fish oil levels and incidence of myocardial infarction in U.S. male physicians. J Am Coll Cardiol 1995, 25:387-94.
• [53]Cummings SR, Nevitt MC, Browner WS, Stone K, Fox KM, Ensrud KE, Cauley J, Black D, Vogt TM: Risk factors for hip fracture in white women. Study of Osteoporotic Fractures Research Group. N Engl J Med 1995, 332:767-73.
• [54]Thun MJ, Peto R, Lopez AD, Monaco JH, Henley SJ, Heath CW, Doll R: Alcohol consumption and mortality among middle-aged and elderly U.S. adults. N Engl J Med 1997, 337:1705-14.
• [55]Lee IM, Hennekens CH, Berger K, Buring JE, Manson JE: Exercise and risk of stroke in male physicians. Stroke 1999, 30:1-6.