Persistence and compliance with newly initiated antihypertensive drug treatment in patients with chronic kidney disease.

BACKGROUND: Patients with chronic kidney disease initiating an antihypertensive drug (AH) treatment must persist and comply with it to slow disease progression and benefit from the reduction of cardiovascular morbidity and mortality. OBJECTIVES: This study evaluates the persistence and compliance with AH treatment and identifies the associated factors among chronic kidney disease patients who initiated AH treatment. METHODS: A population-based cohort study using Quebec administrative data was conducted. Patients who still take any AH 1 year after initiation were considered persistent. Of these patients, those who had ≥80% of days covered with an AH in the year after initiation were considered compliant. Factors associated with persistence and compliance were identified using a modified Poisson regression. RESULTS: Of the 7,119 eligible patients, 78.8% were persistent, 87.7% of whom were compliant with their AH treatment. Compared with patients on diuretic monotherapy, those who initially used angiotensin-converting enzyme inhibitor monotherapy, angiotensin II receptor blocker monotherapy, calcium channel blocker monotherapy, ß-blocker monotherapy, or multidrug therapy were more likely to be persistent. In contrast, individuals who visited their physicians ≥17 times were less likely to be persistent than those who visited between 0 and 8 times. The patients who were more likely to be compliant had initially used an angiotensin-converting enzyme inhibitor, ß-blocker, calcium channel blocker, or multitherapy as opposed to a diuretic. CONCLUSION: A year after initiating AH treatment, nearly a third of chronic kidney disease patients were either not taking an AH or had not been compliant. Factors associated with persistence and compliance could help identify patients who need help in managing their AH treatment.

Suboptimal initiation of dialysis with and without early referral to a nephrologist.

BACKGROUND: Our objective was to examine patients who initiate renal replacement therapy (RRT) at 10 representative Canadian centers, characterize their initiation as inpatient or outpatient and describe their initial type of dialysis access, duration of pre-dialysis care and clinical status at the time of dialysis initiation. We also examined the impact of an optimal dialysis start (i.e. initiated as an outpatient with an arteriovenous fistula, arteriovenous graft or peritoneal dialysis catheter) on subsequent health outcomes. METHODS: Charts of consecutive incident RRT patients were identified from 1 July to 31 December 2006. Information was collected until 6 months after the initiation or until death, transplant or transfer. RESULTS: Three hundred and thirty-nine incident RRT patients were studied: 39.6% initiated as an inpatient; 54% started hemodialysis (HD) with a central venous catheter; 15.3% had <1 month predialysis care, while 64.6% had >1 year. Optimal starts occurred in 39.5% of patients. For HD patients, optimal starts occurred in 19.8%. Suboptimal starts were noted in patients referred <12 months prior to end-stage renal disease (44%) and in patients referred earlier (56%). The composite end point of death, transfusion or subsequent hospitalization was significantly reduced with an optimal start [hazard ratio 0.47 (95% confidence interval 0.32-0.68), P = 0.0001]. CONCLUSIONS: Suboptimal initiation of dialysis is common in patients referred early or late. The benefits of early referral are lost if dialysis is initiated suboptimally. There is a need to identify factors that lead to suboptimal initiation despite early referral.

Impact of age on glomerular filtration estimates.

BACKGROUND: Glomerular filtration decreases progressively with age in adults. Predictive equation should have proper modelling to adequately account for normal senescence. METHODS: Corrected 24-h creatinine clearances (CCLs) were measured in a cohort of 773 outpatients from 18 to 90 years old. Multiple linear regression was used to model the effect of age on glomerular filtration. Comparisons were made with the simplified MDRD and the MAYO equations. Impact of the derived equation was tested in a second cohort of 7551 patients with normal serum creatinine. RESULTS: While all equations show declining function with age, our results suggest that the GFR reduction is progressive after the age of 30 and continue to decline steadily after the age of 60. This leads to a convex curve in the multiple regression analysis that is best fitted by an equation including the quadratic term (age(2)). In contrast, the MDRD equation produces a faster decrease in early adulthood and a flatter curve after the age of 60 while the MAYO equation produces a more linear effect. MDRD results in the normal range are lower than those estimated by the MAYO equation. These equations, as applied on an independent cohort of 7551 normal outpatients from 18 to 102 years, produce different profile of evolution of GFR with age. CONCLUSIONS: Inclusion of a quadratic term for age in the formula estimating GFR results in better modelling of the natural decline of renal function associated with ageing. Furthermore, as GFR steadily declines after the age of 30, a single cut-off value of GFR normality for all ages leads to underdiagnosis of young adults and over diagnosis of elderly individuals. Guidelines should take into account the observed reduction of kidney function with age in normal population for optimal evaluation of eGFR.