Nübling et al. BMC Public Health 2010, 10:428 http://www.biomedcentral.com/1471-2458/10/428 that were interesting in an employee survey - again, we do not know if these institutions participating are repre- sentative for all geriatric care organisations. On the other hand we found no differences in age and gender for our study population as compared to other studies and the official statistics on the German situation in ger- iatric care. We see the major strengths of the formation and use of the COPSOQ-database and of this study in the fol- lowing points: application of a theory-based, compre- hensive and validated survey instrument with a high practicability and usability, and opportunity for compari- son of the situation of employees in geriatric care with a large database with profession specific reference data of the last years. A remark on adjustment for structural biases When sociodemographic characteristics or structural conditions (i.e. part-time work) are unevenly distributed between professions and they are related to the work load parameter under analysis too, then an adjustment of the relation between profession and psychosocial fac- tor could be made and is sometimes postulated. This is true and necessary from a scientific point of view: the comparison between part-time workers (in geriatric care) and full time workers (in other profes- sions) is not “fair”, since it is biased by the confounder weekly workload (hours per week). One could argue: “If geriatric care workers worked more, they would demon- strate higher demand values - the low values measured are biased”. Or: “If they did no on-call duties, their stress and strain would be much lower”. And an adjust- ment would eliminate the effect of the factor and show more average values. This is true and correct, but the other perspective is the one of social reality and prevention: what we see in this survey is the reality in the profession of today’s ger- iatric work in Germany: the employees in fact frequently work part-time and on many special schedules, and - importantly - this seems to be a structural part of their job (at least as it is organized in Germany). In this case adjustment for working schedules would lead to results which do not exist in reality. Adjustment or stratified analysis are therefore neces- sary for the scientific disclosure of the mechanisms behind the self-assessment of psychosocial factors at work (and that is why we did it) - but it may be mis- leading for the discussion and establishment of preven- tive or curative strategies in the today’s reality of the workplace (and that is why we present the “raw” data). Acknowledgements We would like to thank all of the cooperating institutions of geriatric care and all the respondents taking part in the study. Page 11 of 12 Author details 1FFAS - Freiburg Research Centre for Occupational and Social Medicine (Freiburger Forschungsstelle Arbeits- und Sozialmedizin), Bertoldstraße 27, 79098 Freiburg, Germany. 2BGW - Institution for Statutory Accident Insurance and Prevention in the Health and Welfare Services (Berufsgenossenschaft für Gesundheitsdienst und Wohlfahrtspflege), Pappelallee 35/37, 22089 Hamburg, Germany. Authors’ contributions Design of the study: AN, SG, MD, and MN. Recruitment of institutions: SG, MD and AN. Organisation of Survey and data collection: MV and MN. Data analysis: MN. Writing of manuscript: MN, MV, SGS, SG, MD and AN. All authors read and approved the final manuscript. Competing interests The authors declare that they have no competing interests. Received: 19 August 2009 Accepted: 21 July 2010 Published: 21 July 2010 References 1. Organisation for Economic Co-operation and Development (OECD): The OECD Health Project - Long-term Care for Older People. OECD Publishing 2005. 2. Federal Statistical Office and the statistical Offices of the Länder Germany. Wiesbaden: [Demografic Changing in Germany - Impact on hospital treatment and people in need of care in the German federation and of the Länder] Demografischer Wandel in Deutschland - Auswirkungen auf Krankenhausbehandlungen und Pflegebedürftige im Bund und in den Ländern. 2008. 3. Federal Statistical Office Germany: [Statistics in Nursing Care 2007 4th Report] Pflegestatistik 2007 Pflege im Rahmen der Pflegeversicherung 4. Bericht: Ländervergleich - Pflegeheime. Wiesbaden. 2009. 4. Augurzky B, Krolop S, Schmidt H, Terkatz S: [Long-term care insurance, ratings and demography] Pflegeversicherung, Ratings und Demographie - Herausforderungen für deutsche Pflegeheime. RWI: Materials Essen: Rheinisch-Westfälisches Institut für Wirtschaftsforschung 2006, 1-60. 5. Ministry of Family Affairs Senior Citizens Women and Youth: [First Report of the Ministry of Family Affairs, Senior Citizens, Women and Youth for the Situation in long term care institutions and the care for residents] Erster Bericht des Bundesministeriums für Familie, Senioren, Frauen und Jugend über die Situation der Heime und die Betreuung der Bewohnerinnen und Bewohner. 2006. 6. Hasselhorn HM, Tackenberg P, Müller BH: Working conditions and intent to leave the profession among nursing staff in Europe. Stockholm: National Institute for Working Life 2003. 7. Federal Health Monitoring: [Employees in service for out-patients and long term care institutions] Personal in ambulanten Pflegediensten und Pflegeheimen. 2009 [http://www.gbe-bund.de]. 8. Oberski IM, Carter DE, Gray M, Ross J: The community gerontological nurse: themes from a needs analysis. J Adv Nurs 1999, 29(2):454-462. 9. Denton M, Zeytinoglu IU, Davies S, Lian J: Job stress and job dissatisfaction of home care workers in the context of health care restructuring. Int J Health Serv 2002, 32(2):327-357. 10. Brodaty H, Draper B, Low LF: Nursing home staff attitudes towards residents with dementia: strain and satisfaction with work. J Adv Nurs 2003, 44(6):583-590. 11. van den Berg TI, Landeweerd JA, Tummers GE, van Merode GG: A comparative study of organisational characteristics, work characteristics and nurses’ psychological work reactions in a hospital and nursing home setting. Int J Nurs Stud 2006, 43(4):491-505. 12. BGW DAK, Berger J, Nolting HD, Grenz HO: [Health Care Report 2003 Geriatric Care] Gesundheitsreport 2003 Altenpflege. Arbeitsbedingungen und Gesundheit von Pflegekräften in der stationären Altenpflege. Hamburg: BGW, DAK, AOK 2003. 13. Küsgens I: [Health-related absenteeism in geriatric care occupations] Krankheitsbedingte Fehlzeiten in Altenpflegeberufen - Eine Untersuchung der in Altenpflegeeinrichtungen tätigen AOKVersicherten. [Report of absenteeism 2004] Fehlzeiten-Report 2004 Zahlen, Daten, Analysen aus allen Branchen der Wirtschaft- Gesundheitsmanagement in