Association of attrition with mortality: findings from 11 waves over three decades of the Whitehall II study
| Autor: | Mika Kivimäki, Martin J. Shipley, Owen Nicholas, Mifuyu Akasaki, Andrew Steptoe |
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| Rok vydání: | 2019 |
| Předmět: |
Adult
Male medicine.medical_specialty Longitudinal study collider bias Epidemiology media_common.quotation_subject Social epidemiology Epidemiological method 01 natural sciences Article 010104 statistics & probability 03 medical and health sciences 0302 clinical medicine Bias Risk Factors non-response Attrition Medicine Humans selection bias 030212 general & internal medicine Longitudinal Studies 0101 mathematics Mortality media_common Selection bias business.industry withdrawal Public Health Environmental and Occupational Health longitudinal study Middle Aged medicine.disease United Kingdom Cardiovascular Diseases Female Biostatistics business Demography Cohort study |
| Zdroj: | Journal of epidemiology and community health |
| ISSN: | 1470-2738 |
| Popis: | BackgroundAttrition, the loss of participants as a study progresses, is a considerable challenge in longitudinal studies. This study examined whether two forms of attrition, ‘withdrawal’ (formal discontinued participation) and ‘non-response’ (non-response among participants continuing in the study), have different associations with mortality and whether these associations differed across time in a multi-wave longitudinal study.MethodsParticipants were 10 012 civil servants who participated at the baseline of the Whitehall II cohort study with 11 data waves over an average follow-up of 28 years. We performed competing-risks analyses to estimate sub-distribution HRs and 95% CIs, and likelihood ratio tests to examine whether hazards differed between the two forms of attrition. We then applied linear regression to examine any trend of hazards against time.ResultsAttrition rate at data collections ranged between 13% and 34%. There were 495 deaths recorded from cardiovascular disease and 1367 deaths from other causes. Study participants lost due to attrition had 1.55 (95% CI 1.26 to 1.89) and 1.56 (1.39 to 1.76) times higher hazard of cardiovascular and non-cardiovascular mortality than responders, respectively. Hazards for withdrawal and non-response did not differ for either cardiovascular (p value =0.28) or non-cardiovascular mortality (p value =0.38). There was no linear trend in hazards over the 11 waves (cardiovascular mortality p value =0.11, non-cardiovascular mortality p value =0.61).ConclusionAttrition can be a problem in longitudinal studies resulting in selection bias. Researchers should examine the possibility of selection bias and consider applying statistical approaches that minimise this bias. |
| Databáze: | OpenAIRE |
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