Abstract
Objective
Missing item values (MIV) often occur in quality-of-life (QoL) questionnaires. This study aimed to examine whether the use of introductory exemplary questions reduces the number of MIV and what patient-related factors influence effectiveness of such a QoL form training.
Methods
In a randomized controlled study in ten primary care practice settings, a total of 215 consecutively recruited patients with at least one chronic disease were requested to complete the Medical Outcomes Study 36 Items Short Form (SF-36) questionnaire, German version 1.0. Prior to filling out the QoL form, a sample of randomly selected patients answered three simple written questions similar in wording and appearance to the original SF-36 questionnaire.
Results
In total, 126 (58.6%) patients completed the SF-36 questionnaire without MIV. Despite MIV the forms of 46 (21.4%) patients were still computable, i.e., scoring of scales was possible after use of the standardized SF-36 imputation algorithm. After the imputation procedure, MIV significantly hampered generating computable sum scales in 29 (26.6%) of the control group and 14 (13.2%) of the interventional group (P < 0.05). A univariate analysis suggested no evidence that the number of MIV was reduced by the intervention. However, intervention led to a significant decrease of MIV in males but not in females. The education status affected the number of missing data independent of intervention.
Conclusion
This cross-sectional study showed that the prior use of three self-created questions similar in wording and appearance to the SF-36 questionnaire significantly reduces MIV in male patients. School qualification of QoL respondents inversely correlated with the number of questionnaire MIV, but independent of education status all subjects did benefit from the QoL form training.
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References
Barclay S, Todd C, Finlay I, Grande G, Wyatt P (2002) Not another questionnaire! Maximizing the response rate, predicting non-response and assessing non-response bias in postal questionnaires studies of GPs. Fam Pract 19:105–111
Bullinger M, Kirchberger I (1998) German manual SF-36 questionnaire. Hofgrefe, Göttingen
Bullinger M, Morfeld M, Kohlmann T et al (2003) SF-36 health survey in rehabilitation research. Findings from the North German Network for Rehabilitation Research within the Rehabilitation Research Funding Program. Rehabilitation 42:218–225
Donders AR, van der Heijden GJ, Stijnen T, Moons KG (2006) Review: a gentle introduction to imputation of missing values. J Clin Epidemiol 59:1087–1091
Engels JM, Diehr P (2003) Imputation of missing longitudinal data: a comparison of methods. J Clin Epidemiol 56:968–976
Fayers PM, Curran D, Machin D (1998) Incomplete quality of life data in randomized trials: missing items. Stat Med 17:679–696
Fielding S, Maclennan G, Cook JA, Ramsay CR (2008) A review of RCTs in four medical journals to assess the use of imputation to overcome missing data in quality of life outcomes. Trials 9:51. doi:10.1186/1745-6215-9-51
Jenkinson C, Coulter A, Wright L (1993) Short form 36 (SF36) health survey questionnaire: normative data for adults of working age. Br Med J 306:1437–1440
Lamberts H, Wood M (1987) ICPC, International classification of primary care. Oxford University Press, Oxford
Little RJ, Rubin DB (1989) The analysis of social science data with missing values. Soc Methods Res 18:292–326
Molenberghs G, Kenward MG (2007) Missing data in clinical studies. Wiley, New York
Morfeld M, Dietsche S, Bürger W, Koch U (2003) Der SF-12—Das Problem der Missing Data. Diagnostica 49:129–135
Reulen RC, Zeegers MP, Jenkinson C, Lancashire ER, Winter DL, Jenney ME, Hawkins MM (2006) The use of SF-36 questionnaire in adult survivors of childhood cancer: evaluation of data quality, score reliability, and scaling assumptions. Health Qual Life Outcomes 4:77. doi:10.1186/1477-7525-4-77
Rubin DB (1976) Interference and missing data. Biometrika 72:359–364
Shrive FM, Stuart H, Quan H, Ghali WA (2006) Dealing with missing data in a multi-question depression scale: a comparison of imputation methods. BMC Med Res Methodol 6:57
Ware J, Sherbourne C (1992) The MOS 36-item short-form health survey (SF-36): I. Conceptual framework and item selection. Med Care 30:473–483
White IR, Thompson SG (2005) Adjusting for partially missing baseline measurements in randomized trials. Stat Med 24:993–1007
Wood AM, White IR, Thompson SG (2004) Are missing outcome data adequately handled? A review of published randomized controlled trials in major medical journals. Clin Trials 1:368–376
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Müller-Bühl, U., Franke, B., Hermann, K. et al. Lowering missing item values in quality-of-life questionnaires: an interventional study. Int J Public Health 56, 63–69 (2011). https://doi.org/10.1007/s00038-009-0113-z
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DOI: https://doi.org/10.1007/s00038-009-0113-z