Prevalence estimates of chronic kidney disease in Canada: results of a nationally representative survey

Note: CI = confidence interval, CKD-EPI = Chronic Kidney Disease Epidemiology Collaboration, MDRD = Modification of Diet in Renal Disease, NA = not available.

↵* See Box 1 for classification of the stages of chronic kidney disease.

↵† Missing observations = 100 (owing to missing values for serum creatinine).

↵‡ Unweighted numbers of participants aged 18–79 years (excluding pregnant women).

↵§ Weighted prevalence was calculated with the use of sampling weights provided by Statistics Canada that accounted for representativeness and nonresponse.

↵¶ Unweighted numbers of participants (and weighted proportions with 95% CIs) by stage of disease according to the CKD-EPI equation are as follows: normal: 3073 (87.4%, 85.6%–89.1%); stage 1: 238 (6.9%, 5.7%–8.4%); stage 2: 115 (2.5%, 1.9%–3.3%); stage 3: 151 (2.9%, 2.3%–3.6%); stage 4: 9 (prevalence estimate NA^‡‡); stage 5: 3 (prevalence estimate NA^‡‡).

↵** Unweighted numbers of participants (and weighted proportions with 95% CIs) by stage of disease according to the MDRD equation are as follows: normal: 3028 (86.6%, 84.7%–88.3%); stage 1: 197 (5.4%, 4.2%–7.1%); stage 2: 153 (3.9%, 3.2%–4.9%); stage 3: 202 (3.8%, 3.0%–4.8%); stage 4: 8 (prevalence estimate NA^‡‡); stage 5: 3 (prevalence estimate NA^‡‡).

↵†† Excludes participants with diabetes (n = 300 [7.2%]) and hypertension (n = 759 [17.6%]), as defined in Methods.

↵‡‡ Prevalence estimate cannot be reported (coefficient of variation [CV] > 33.3%).

↵§§ Marginal sampling variability (16% < CV < 33%); interpret with caution.

Note: BMI = body mass index, CI = confidence interval, CRP = C-reactive protein, HDL = high-density lipoprotein, LDL = low-density lipoprotein.

↵* Prevalence estimates are age-standardized to the weighted survey population aged 18–79 (excluding pregnant women) by 20-year age groups.

↵† p < 0.05 for test of difference in prevalence of risk factor for cardiovascular disease between participants with and without chronic kidney disease.

↵‡ Unweighted numbers of study participants aged 18–79 years (excluding those reporting previous or existing heart condition, n = 297). Missing observations = 95 (presence of chronic kidney disease unknown owing to missing values for serum creatinine). Reports of previous or existing heart condition defined as participant having heart disease, ever having had a heart attack, having a heart condition that limited physical activity or taking drugs for any cardiovascular condition.

↵§ See Methods for definitions of diabetes and hypertension.

↵¶ Defined as waist circumference ≥ 94 cm for men and ≥ 80 cm for women.

↵** Daily smoker = respondents who reported smoking daily and those who reported smoking occasionally but who were former daily smokers; former daily smokers = respondents who reported being nonsmokers but who were former daily smokers. Occasional smokers (n = 57) were not included in the calculation of smoking status owing to small numbers.

↵†† A total of 1796 participants met the fasting criteria; 137 were excluded from this table because they had a current or previous heart condition. Missing observations = 30 (presence of chronic kidney disease unknown owing to missing values for serum creatinine).

↵‡‡ Defined as < 1.03 mmol/L for men and < 1.3 mmol/L for women.

↵§§ Marginal sampling variability (coefficient of variation [CV] > 16% and < 33%); interpret with caution. All other estimates had CV values < 16.6%.