A comparison of the recording of comorbidity in primary and secondary care by using the Charlson Index to predict short-term and long-term survival in a routine linked data cohort
OBJECTIVE: Hospital admission records provide snapshots of clinical histories for a subset of the population admitted to hospital. In contrast, primary care records provide continuous clinical histories for complete populations, but might lack detail about inpatient stays. Therefore, combining prima...
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| Format: | Article |
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BMJ Publishing Group
2015
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| Online Access: | https://eprints.nottingham.ac.uk/32057/ |
| _version_ | 1848794326223552512 |
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| author | Crooks, Colin J. West, Joe Card, Timothy R. |
| author_facet | Crooks, Colin J. West, Joe Card, Timothy R. |
| author_sort | Crooks, Colin J. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | OBJECTIVE: Hospital admission records provide snapshots of clinical histories for a subset of the population admitted to hospital. In contrast, primary care records provide continuous clinical histories for complete populations, but might lack detail about inpatient stays. Therefore, combining primary and secondary care records should improve the ability of comorbidity scores to predict survival in population-based studies, and provide better adjustment for case-mix differences when assessing mortality outcomes.
DESIGN: Cohort study.
SETTING: English primary and secondary care 1 January 2005 to 1 January 2010.
PARTICIPANTS: All patients 20 years and older registered to a primary care practice contributing to the linked Clinical Practice Research Datalink from England.
OUTCOME: The performance of the Charlson index with mortality was compared when derived from either primary or secondary care data or both. This was assessed in relation to short-term and long-term survival, age, consultation rate, and specific acute and chronic diseases.
RESULTS: 657,264 people were followed up from 1 January 2005. Although primary care recorded more comorbidity than secondary care, the resulting C statistics for the Charlson index remained similar: 0.86 and 0.87, respectively. Higher consultation rates and restricted age bands reduced the performance of the Charlson index, but the index's excellent performance persisted over longer follow-up; the C statistic was 0.87 over 1 year, and 0.85 over all 5 years of follow-up. The Charlson index derived from secondary care comorbidity had a greater effect than primary care comorbidity in reducing the association of upper gastrointestinal bleeding with mortality. However, they had a similar effect in reducing the association of diabetes with mortality.
CONCLUSIONS: These findings support the use of the Charlson index from linked data and show that secondary care comorbidity coding performed at least as well as that derived from primary care in predicting survival. |
| first_indexed | 2025-11-14T19:14:25Z |
| format | Article |
| id | nottingham-32057 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:14:25Z |
| publishDate | 2015 |
| publisher | BMJ Publishing Group |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-320572020-05-04T17:11:20Z https://eprints.nottingham.ac.uk/32057/ A comparison of the recording of comorbidity in primary and secondary care by using the Charlson Index to predict short-term and long-term survival in a routine linked data cohort Crooks, Colin J. West, Joe Card, Timothy R. OBJECTIVE: Hospital admission records provide snapshots of clinical histories for a subset of the population admitted to hospital. In contrast, primary care records provide continuous clinical histories for complete populations, but might lack detail about inpatient stays. Therefore, combining primary and secondary care records should improve the ability of comorbidity scores to predict survival in population-based studies, and provide better adjustment for case-mix differences when assessing mortality outcomes. DESIGN: Cohort study. SETTING: English primary and secondary care 1 January 2005 to 1 January 2010. PARTICIPANTS: All patients 20 years and older registered to a primary care practice contributing to the linked Clinical Practice Research Datalink from England. OUTCOME: The performance of the Charlson index with mortality was compared when derived from either primary or secondary care data or both. This was assessed in relation to short-term and long-term survival, age, consultation rate, and specific acute and chronic diseases. RESULTS: 657,264 people were followed up from 1 January 2005. Although primary care recorded more comorbidity than secondary care, the resulting C statistics for the Charlson index remained similar: 0.86 and 0.87, respectively. Higher consultation rates and restricted age bands reduced the performance of the Charlson index, but the index's excellent performance persisted over longer follow-up; the C statistic was 0.87 over 1 year, and 0.85 over all 5 years of follow-up. The Charlson index derived from secondary care comorbidity had a greater effect than primary care comorbidity in reducing the association of upper gastrointestinal bleeding with mortality. However, they had a similar effect in reducing the association of diabetes with mortality. CONCLUSIONS: These findings support the use of the Charlson index from linked data and show that secondary care comorbidity coding performed at least as well as that derived from primary care in predicting survival. BMJ Publishing Group 2015-06-05 Article PeerReviewed Crooks, Colin J., West, Joe and Card, Timothy R. (2015) A comparison of the recording of comorbidity in primary and secondary care by using the Charlson Index to predict short-term and long-term survival in a routine linked data cohort. BMJ Open, 5 (6). e007974/1-e007974/8. ISSN 2044-6055 http://bmjopen.bmj.com/content/5/6/e007974 10.1136/bmjopen-2015-007974 10.1136/bmjopen-2015-007974 10.1136/bmjopen-2015-007974 |
| spellingShingle | Crooks, Colin J. West, Joe Card, Timothy R. A comparison of the recording of comorbidity in primary and secondary care by using the Charlson Index to predict short-term and long-term survival in a routine linked data cohort |
| title | A comparison of the recording of comorbidity in primary and secondary care by using the Charlson Index to predict short-term and long-term survival in a routine linked data cohort |
| title_full | A comparison of the recording of comorbidity in primary and secondary care by using the Charlson Index to predict short-term and long-term survival in a routine linked data cohort |
| title_fullStr | A comparison of the recording of comorbidity in primary and secondary care by using the Charlson Index to predict short-term and long-term survival in a routine linked data cohort |
| title_full_unstemmed | A comparison of the recording of comorbidity in primary and secondary care by using the Charlson Index to predict short-term and long-term survival in a routine linked data cohort |
| title_short | A comparison of the recording of comorbidity in primary and secondary care by using the Charlson Index to predict short-term and long-term survival in a routine linked data cohort |
| title_sort | comparison of the recording of comorbidity in primary and secondary care by using the charlson index to predict short-term and long-term survival in a routine linked data cohort |
| url | https://eprints.nottingham.ac.uk/32057/ https://eprints.nottingham.ac.uk/32057/ https://eprints.nottingham.ac.uk/32057/ |