title: Comorbidity as a driver of adverse outcomes in people with chronic kidney disease.
abstract: Chronic kidney disease (CKD) is associated with poor outcomes, perhaps due to a high burden of comorbidity. Most studies of CKD populations focus on concordant comorbidities, which cause CKD (such as hypertension and diabetes) or often accompany CKD (such as heart failure or coronary disease). Less is known about the burden of mental health conditions and discordant conditions (those not concordant but still clinically relevant, like dementia or cancer). Here we did a retrospective population-based cohort study of 530,771 adults with CKD residing in Alberta, Canada between 2003 and 2011. Validated algorithms were applied to data from the provincial health ministry to assess the presence/absence of 29 chronic comorbidities. Linkage between comorbidity burden and adverse clinical outcomes (mortality, hospitalization or myocardial infarction) was examined over median follow-up of 48 months. Comorbidities were classified into three categories: concordant, mental health/chronic pain, and discordant. The median number of comorbidities was 1 (range 0-15) but a substantial proportion of participants had 3 and more, or 5 and more comorbidities (25 and 7%, respectively). Concordant comorbidities were associated with excess risk of hospitalization, but so were discordant comorbidities and mental health conditions. Thus, discordant comorbidities and mental health conditions as well as concordant comorbidities are important independent drivers of the adverse outcomes associated with CKD.
authors.affiliation: Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Marcello
authors.initials: M
authors.lastname: Tonelli
authors.affiliation: Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Natasha
authors.initials: N
authors.lastname: Wiebe
authors.affiliation: Population Health Sciences Division, Medical Research Institute, University of Dundee, Dundee, UK.
authors.forename: Bruce
authors.initials: B
authors.lastname: Guthrie
authors.affiliation: Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: James
authors.affiliation: Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Hude
authors.initials: H
authors.lastname: Quan
authors.affiliation: Department of Family Medicine, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
authors.forename: Martin
authors.initials: M
authors.lastname: Fortin
authors.affiliation: Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Scott W
authors.initials: SW
authors.lastname: Klarenbach
authors.affiliation: Alberta Health Services, Edmonton, Alberta, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Sargious
authors.affiliation: Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Sharon
authors.initials: S
authors.lastname: Straus
authors.affiliation: Alberta Health Services, Edmonton, Alberta, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Lewanczuk
authors.affiliation: Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Ronksley
authors.affiliation: Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Braden J
authors.initials: BJ
authors.lastname: Manns
authors.affiliation: Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Brenda R
authors.initials: BR
authors.lastname: Hemmelgarn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000416:Alberta / Q000453:epidemiology; D016208:Databases, Factual; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology; D011379:Prognosis; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult