Prevalence and Demographics of CKD in Canadian Primary Care Practices: A Cross-sectional Study

Abstract

Introduction: Surveillance systems enable optimal care delivery and appropriate resource allocation, yet Canada lacks a dedicated surveillance system for chronic kidney disease (CKD). Using data from the Canadian Primary Care Sentinel Surveillance Network (CPCSSN), a national chronic disease surveillance system, this study describes the geographic, sociodemographic, and clinical variations in CKD prevalence in the Canadian primary care context.

Methods: This cross-sectional study included 559,745 adults in primary care in 5 provinces across Canada from 2010 through 2015. Data were analyzed by geographic (urban or rural residence), sociodemographic (age, sex, deprivation index), and clinical (medications prescribed, comorbid conditions) factors, using data from CPCSSN and the Canadian Deprivation Index. CKD stage 3 or higher was defined as 2 estimated glomerular filtration rate (eGFR) values of <60 ml/min per 1.73 m² more than 90 days apart as of January 1, 2015.

Results: Prevalence of CKD was 71.9 per 1000 individuals and varied by geography, with the highest prevalence in rural settings compared with urban settings (86.2 vs. 68.4 per 1000). CKD was highly prevalent among individuals with 3 or more other chronic diseases (281.7 per 1000). Period prevalence of CKD indicated a slight decline over the study duration, from 53.4 per 1000 in 2010 to 46.5 per 1000 in 2014.

Conclusion: This is the first study to estimate the prevalence of CKD in primary care in Canada at a national level. Results may facilitate further research, prioritization of care, and quality improvement activities to identify gaps and improvement in CKD care.

Keywords: chronic kidney disease (CKD); electronic medical record; epidemiology; prevalence; primary care; surveillance.

Figure 1

Participation of Canadian Primary Care Sentinel Surveillance Network (CPCSSN) networks by province. Blue, nonparticipating CPCSSN networks; orange, participating CPCSSN networks. Primary care research networks contributing data to the CPCSSN: 1, British Columbia Primary Care Research Network (BCPCReN); 2, Northern Alberta Primary Care Research Network (NAPCReN); 3, Southern Alberta Primary Care Research Network (SAPCReN); 4, Manitoba Primary Care Research Network (MaPCReN); 5, Deliver Primary Healthcare Information Project (DELPHI); 6, McMaster University Sentinel and Information Collaboration (MUSIC); 7, University of Toronto Practice-Based Research Network (UTOPIAN); 8, The Eastern Ontario Network (EON); 9, Ottawa Practice Enhancement Network (OPEN); 10, Réseau de recherche en soins primaires de l’Université de Montréal (RRSPUM); 11, Maritime Family Practice Research Network (MaRNet-FP); 12, Atlantic Practice-Based Research Network (APBRN).

Figure 2

Selection of study population. CPCSSN, Canadian Primary Care Sentinel Surveillance Network; eGFR, estimated glomerular filtration rate; PCP, primary care provider.

Figure 3

(a) Overall prevalence of chronic kidney disease (CKD) (2010–2015) by deprivation index, by CKD stage. Level of deprivation of Canadian Deprivation Index score: 1 (least deprived), dark blue; 2, red; 3, green; 4, purple; 5 (most deprived), light blue. (b) Overall prevalence of CKD (2010–2015) by urban/rural residence, stratified by CKD stage. Participant residence: urban (blue); rural (red).

Figure 4

(a) Period prevalence of chronic kidney disease (CKD) by year and deprivation index. Level of deprivation of Canadian Deprivation Index score: 1 (least deprived), dark blue; 2, red; 3, green; 4, purple; 5 (most deprived), light blue. (b) Period prevalence of CKD by year and urban/rural residence. Participant residence: urban (blue); rural (red).