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Utilizing national patient-register data to control for comorbidity in prognostic studies.

Nilssen Y, Strand TE, Wiik R, Bakken IJ, Yu XQ, O'Connell DL, Møller B - Clin Epidemiol (2014)

Bottom Line: When the PRI was added to the model including age and sex, the age effects were reduced by up to 38% for patients older than 50 years.All measures of model fit improved for the PRI model.Adjustment for comorbidity is especially important for patients 50 years of age or older, and its effect on 1-year mortality is almost comparable to the age effect.

View Article: PubMed Central - PubMed

Affiliation: Department of Registration, Cancer Registry of Norway, Oslo, Norway.

ABSTRACT

Objective: To construct an updated comorbidity index (Patient Register Index [PRI]) using national data collections from Norway and compare its predictive ability of 1-year mortality with the Charlson Comorbidity Index (CCI).

Materials and methods: Data regarding over 1.11 million patients registered in the Norwegian Patient Register in 2010 and 2011 were used to construct the PRI. The PRI was evaluated by comparing its model fit and discrimination with the CCI.

Results: Compared with the CCI, the PRI weights decreased for six, increased for four, and were unchanged for seven diseases. When the PRI was added to the model including age and sex, the age effects were reduced by up to 38% for patients older than 50 years. All measures of model fit improved for the PRI model.

Conclusion: Adjustment for comorbidity is especially important for patients 50 years of age or older, and its effect on 1-year mortality is almost comparable to the age effect. The PRI is based on more recent data than the CCI, and is more representative of the general population due to its construction.

No MeSH data available.


Related in: MedlinePlus

The age effects (hazard ratios) relative to the age-group 50–54 years (log scale), for different models based on patients not admitted for any of the 17 Charlson Comorbidity Index (CCI) diseases registered in the Norwegian Patient Register in 2010–2011.Abbreviation: PRI, Patient Register Index.
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f4-clep-6-395: The age effects (hazard ratios) relative to the age-group 50–54 years (log scale), for different models based on patients not admitted for any of the 17 Charlson Comorbidity Index (CCI) diseases registered in the Norwegian Patient Register in 2010–2011.Abbreviation: PRI, Patient Register Index.

Mentions: Among patients aged 50 years or older who were not admitted to hospital due to any of the 17 CCI diseases, the ten most common categories for admission are listed in Table 3. ICD-10 code H25, “Senile cataract” (4.2%), and R07, “Pain in throat and chest” (3.0%), were the two most common conditions. The rest contributed with less than 3% each. Figure 4 shows the change in the effect of age when either of the two comorbidity indices was added to the base model for these patients. Including the PRI in the model led to a reduction in the effect of age for all age-groups, ranging from 3.5% in the 55–59-year group to 38% in the 95+ year group. This reduction was greater than the reduction observed for the CCI model.


Utilizing national patient-register data to control for comorbidity in prognostic studies.

Nilssen Y, Strand TE, Wiik R, Bakken IJ, Yu XQ, O'Connell DL, Møller B - Clin Epidemiol (2014)

The age effects (hazard ratios) relative to the age-group 50–54 years (log scale), for different models based on patients not admitted for any of the 17 Charlson Comorbidity Index (CCI) diseases registered in the Norwegian Patient Register in 2010–2011.Abbreviation: PRI, Patient Register Index.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4216019&req=5

f4-clep-6-395: The age effects (hazard ratios) relative to the age-group 50–54 years (log scale), for different models based on patients not admitted for any of the 17 Charlson Comorbidity Index (CCI) diseases registered in the Norwegian Patient Register in 2010–2011.Abbreviation: PRI, Patient Register Index.
Mentions: Among patients aged 50 years or older who were not admitted to hospital due to any of the 17 CCI diseases, the ten most common categories for admission are listed in Table 3. ICD-10 code H25, “Senile cataract” (4.2%), and R07, “Pain in throat and chest” (3.0%), were the two most common conditions. The rest contributed with less than 3% each. Figure 4 shows the change in the effect of age when either of the two comorbidity indices was added to the base model for these patients. Including the PRI in the model led to a reduction in the effect of age for all age-groups, ranging from 3.5% in the 55–59-year group to 38% in the 95+ year group. This reduction was greater than the reduction observed for the CCI model.

Bottom Line: When the PRI was added to the model including age and sex, the age effects were reduced by up to 38% for patients older than 50 years.All measures of model fit improved for the PRI model.Adjustment for comorbidity is especially important for patients 50 years of age or older, and its effect on 1-year mortality is almost comparable to the age effect.

View Article: PubMed Central - PubMed

Affiliation: Department of Registration, Cancer Registry of Norway, Oslo, Norway.

ABSTRACT

Objective: To construct an updated comorbidity index (Patient Register Index [PRI]) using national data collections from Norway and compare its predictive ability of 1-year mortality with the Charlson Comorbidity Index (CCI).

Materials and methods: Data regarding over 1.11 million patients registered in the Norwegian Patient Register in 2010 and 2011 were used to construct the PRI. The PRI was evaluated by comparing its model fit and discrimination with the CCI.

Results: Compared with the CCI, the PRI weights decreased for six, increased for four, and were unchanged for seven diseases. When the PRI was added to the model including age and sex, the age effects were reduced by up to 38% for patients older than 50 years. All measures of model fit improved for the PRI model.

Conclusion: Adjustment for comorbidity is especially important for patients 50 years of age or older, and its effect on 1-year mortality is almost comparable to the age effect. The PRI is based on more recent data than the CCI, and is more representative of the general population due to its construction.

No MeSH data available.


Related in: MedlinePlus