Abstract
Background
This study investigates the accuracy of the reporting of medication use by proxy- and self-respondents, and it compares the prognostic value of the number of medications from survey and registry data for predicting mortality across self- and proxy-respondents.
Methods
The study is based on the linkage of the Longitudinal Study of Aging Danish Twins and the Danish 1905–Cohort Study with the Danish National Prescription Registry. We investigated the concordance between survey and registry data, and the prognostic value of medication use when assessed using survey and registry data, to predict mortality for self- and proxy-respondents at intake surveys.
Results
Among self-respondents, the agreement was moderate (κ = 0.52–0.58) for most therapeutic groups, whereas among proxy-respondents, the agreement was low to moderate (κ = 0.36–0.60). The magnitude of the relative differences was, generally, greater among proxies than among self-respondents. Each additional increase in the total number of medications was associated with 7%–8% mortality increase among self- and 4%–6% mortality increase among proxy-respondents in both the survey and registry data. The predictive value of the total number of medications estimated from either data source was lower among proxies (c-statistic = 0.56–0.58) than among self-respondents (c-statistic = 0.74).
Conclusions
The concordance between survey and registry data regarding medication use and the predictive value of the number of medications for mortality were lower among proxy- than among self-respondents.
This study investigates the accuracy of the reporting of medication use by proxy- and self-respondents, and it compares the prognostic value of the number of medications from survey and registry data for predicting mortality across self- and proxy-respondents.
Methods
The study is based on the linkage of the Longitudinal Study of Aging Danish Twins and the Danish 1905–Cohort Study with the Danish National Prescription Registry. We investigated the concordance between survey and registry data, and the prognostic value of medication use when assessed using survey and registry data, to predict mortality for self- and proxy-respondents at intake surveys.
Results
Among self-respondents, the agreement was moderate (κ = 0.52–0.58) for most therapeutic groups, whereas among proxy-respondents, the agreement was low to moderate (κ = 0.36–0.60). The magnitude of the relative differences was, generally, greater among proxies than among self-respondents. Each additional increase in the total number of medications was associated with 7%–8% mortality increase among self- and 4%–6% mortality increase among proxy-respondents in both the survey and registry data. The predictive value of the total number of medications estimated from either data source was lower among proxies (c-statistic = 0.56–0.58) than among self-respondents (c-statistic = 0.74).
Conclusions
The concordance between survey and registry data regarding medication use and the predictive value of the number of medications for mortality were lower among proxy- than among self-respondents.
| Original language | English |
|---|---|
| Pages (from-to) | 742-747 |
| Journal | Journals of Gerontology Series A - Biological Sciences and Medical Sciences |
| Volume | 74 |
| Issue number | 5 |
| Early online date | 19 Jun 2018 |
| DOIs | |
| Publication status | Published - May 2019 |
Keywords
- Proxy
- Self-respondents
- Medication use
- Register study
- Denmark
Access to Document
- Oksuzyan_2020_JoG-MS_Is-who-you-ask_CC
Copyright © The Author(s) 2018. Published by Oxford University Press on behalf of The Gerontological Society of America. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited.