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Centre for Policy on Ageing | |
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The effect of the duration of follow-up in mortality analysis
— the temporal pattern of different predictors | | Author(s) | Bettina Meinow, Ingemar Käreholt, Marti G Parker |
| Journal title | Journals of Gerontology: Series B, Psychological Sciences and Social Sciences, vol 59B, no 3, May 2004 |
| Pages | pp S181-S189 |
| Source | http://www.geron.org |
| Keywords | Death rate [statistics] ; Social characteristics [elderly] ; Mental health [elderly] ; Longitudinal surveys ; Sweden. |
| Annotation | A model is presented of the mechanisms affecting how time since baseline affects the correlation between mortality and commonly used predictors. This study originates from an interview survey of 421 community-based people aged 75+ that was conducted in 1986 in Tierp, a rural community in central Sweden. 15-year mortality rates were analysed using hazard regression. Rather than using average risk over the whole follow-up time, this study looks at temporal differences in predictor strength. All of the studied health variables, living conditions and life satisfaction were much stronger predictors of mortality during the first one or two years of follow-up than during later years. Gender, social contacts and mental status were about equally correlated to mortality throughout the period. Of the presented mechanisms affecting predictive strength, results suggest the importance of the instability of predictors over time. This is particularly so for older populations, for whom predictors can change rapidly (e.g. health are strongest in the short-term), revealing a lower average mortality risk for longer follow-ups. More stable variables (e.g. gender or social contacts) are not affected by the length of follow-up. When average risk is studied over a longer follow-up, insignificant results may hide significant effects during a part of the follow-up. These findings are relevant for studies that examine any kind of outcome after a follow-up. (RH). |
| Accession Number | CPA-041103215 A |
| Classmark | S5: F: D: 3J: 76P |
Data © Centre for Policy on Ageing |
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| ...from the Ageinfo database published by Centre for Policy on Ageing. |
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