Early specialist care for diabetes: who benefits most? A propensity score-matched cohort study

AIMS

To examine whether early endocrinologist care reduces the risk of cardiovascular complications among newly diagnosed patients with diabetes of differing complexity.

METHODS

We conducted a population-based propensity score-matched cohort study using provincial health data from Ontario, Canada. Adults (≥ 30 years) diagnosed with diabetes between 1 April 1998 and 31 March 2006 who received endocrinologist care in the first year of diagnosis were matched to a comparison group receiving primary care alone (N = 79 020) based on propensity scores and medical complexity (assigned using information on chronic conditions). Individuals were followed for 3- and 5-year outcomes, including non-fatal acute myocardial infarction or coronary heart disease death (primary endpoint), major cardiovascular events (acute myocardial infarction, stroke) or all-cause death, amputation and end-stage renal disease.

RESULTS

Among medically complex patients, early endocrinologist care was associated with a lower 3-year incidence of the primary endpoint (hazard ratio 0.89, 95% CI 0.78-1.01) and major cardiovascular events or all-cause death (hazard ratio 0.91, 95% CI 0.85-0.97). These effects persisted after accounting for a higher incidence of end-stage renal disease on follow-up and were greatest in those with ≥ 3 visits to an endocrinologist (primary endpoint: hazard ratio 0.69, 95% CI 0.56-0.86 and 0.61, 95% CI 0.45-0.82, for unadjusted and end-stage renal disease adjusted analyses, respectively). In contrast, no benefit was observed in the non-medically complex subgroup. Overall effects were similar at 5 years.

CONCLUSIONS

Early endocrinologist care is associated with a lower incidence of cardiovascular events and death among newly diagnosed patients with diabetes who have comorbid medical conditions.

Risk of kidney stones with surgical intervention in living kidney donors

A kidney stone in a person with a solitary kidney requires urgent attention, which may result in surgical and/or hospital attention. We conducted a matched retrospective cohort study to determine if living kidney donors compared to healthy nondonors have a higher risk of: (i) kidney stones with surgical intervention, and (ii) hospital encounters for kidney stones. We reviewed all predonation charts for living kidney donations from 1992 to 2009 at five major transplant centers in Ontario, Canada, and linked this information to healthcare databases. We selected nondonors from the healthiest segment of the general population and matched 10 nondonors to every donor. Of the 2019 donors and 20 190 nondonors, none had evidence of kidney stones prior to cohort entry. Median follow-up time was 8.4 years (maximum 19.7 years; loss to follow-up <7%). There was no difference in the rate of kidney stones with surgical intervention in donors compared to nondonors (8.3 vs. 9.7 events/10 000 person-years; rate ratio 0.85; 95% confidence interval [CI] 0.47-1.53). Similarly there was no difference in the rate of hospital encounters for kidney stones (12.1 vs. 16.1 events/10 000 person-years; rate ratio 0.75; 95% CI 0.45-1.24). These interim results are reassuring for the safety of living kidney donation.

Bone mineral density by DXA and HR pQCT can discriminate fracture status in men and women with stages 3 to 5 chronic kidney disease

Fractures are common in chronic kidney disease (CKD). We determined if bone mineral density testing by dual energy X-ray absorptiometry (DXA) and high resolution peripheral quantitative computed tomography (HR pQCT) could discriminate fracture status in CKD patients. Both tests were able to discriminate fracture status. Further, the addition of HR pQCT measurements to DXA measurements did not improve fracture discrimination.

INTRODUCTION

The optimal method to identify individuals with CKD at high fracture risk is unknown.

METHODS

We determined if bone mineral density (BMD) by DXA and HR pQCT could discriminate fracture status in 211 adult men and women with stages 3 to 5 CKD, attending predialysis clinics in Toronto Canada, using logistic regression. Results are expressed as the odds ratio (OR) of fracture (prevalent vertebral and/or low trauma since age 40 years) per standard deviation decrease in the predictor adjusted for age, weight, sex, and CKD stage. We constructed receiver operating characteristic curves to examine the discriminative ability of BMD measures for fracture.

RESULTS

Most participants were Caucasian men with a mean age of 63.3 ± 15.5 years. There were 77 fractures in 74 participants. Decreases in BMD were associated with increased fracture risk: OR = 1.56 (95% confidence interval (CI), 1.41 to 1.71) for BMD by DXA at the ultradistal radius, and OR = 1.24 (95% CI, 1.12 to 1.36) for cortical area by HR pQCT. Further, while both tests were able to discriminate fracture status, the addition of HR pQCT measures to BMD by DXA did not improve fracture discrimination ability.

CONCLUSIONS

Among CKD patients not yet requiring renal replacement therapy, BMD by DXA is able to discriminate fracture status.

The Vascular Access Questionnaire: assessing patient-reported views of vascular access

BACKGROUND

The use of central venous catheters for vascular access in hemodialysis (HD) patients is associated with an increased risk of complications compared to arteriovenous fistulas (AVF). Despite this, catheter use remains high and patient satisfaction may be an important driver of catheter use.

METHODS

We developed the Vascular Access Questionnaire (VAQ) to measure patient-reported views of their vascular access. Chronic HD patients at two centers were asked to rate how bothered they were by 17 access-related problems. VAQ symptom scores were compared between patients using catheters and those using fistulas for vascular access.

RESULTS

Two hundred and twenty-two patients were eligible for the study. Symptom score was not different between patients using catheters and those using fistulas (p=0.36). However, patients using fistulas were more likely to be at least moderately bothered by pain, bleeding, bruising, swelling, and the appearance of their access than patients using catheters. Elderly patients reported lower symptom scores with catheters than fistulas.

CONCLUSIONS

Patients appear to be primarily concerned with the appearance of their access and cannulation-related complications, particularly the elderly. Better education about the risk of adverse events with catheters and the implementation of measures aimed at reducing cannulation-related complications may help to increase fistula rates and improve patient satisfaction with their vascular access.

Challenges for randomized controlled trials in nephrology: illustrations in vascular access science and care

While randomized controlled trials (RCTs) are the gold standard for evidence in medicine, there is an overall paucity of RCTs in nephrology compared with other medical subspecialties. Consequently, the management of the dialysis population is often guided by nephrology clinical practice guidelines that are largely based on observational data or expert opinion. This review examines problems related to designing, conducting and completing RCTs in nephrology, highlighting major challenges, successes and frustrations, with specific examples as they pertain to the science of hemodialysis vascular access and their impact on clinical practice guidelines.

Central venous catheter outcomes in nocturnal hemodialysis

Central venous catheter (CVC) as hemodialysis (HD) access is associated with great morbidity and mortality in the end-stage renal disease population. Quotidian, nocturnal HD (NHD) is a novel dialysis modality associated with cardiovascular and quality of life benefits, yet there is a concern of a potential increase in vascular access-related complications through patient-directed access cannulation. We aimed to determine catheter incidence and prevalence in the NHD population and to compare rates of catheter-related: infection, thrombolytic administration, hospitalization, survival, and reasons for their loss before and after conversion to NHD. This observational cohort consisted of incident and prevalent NHD patients between 1 November 1993 and 31 May 2005. Rate comparisons were determined by Poisson analysis and catheter survival by Kaplan-Meier curves. Eighty-one CVCs in 33 patients accounted for 17 150 CVC days (CVCD); 40 CVCs were exclusively used for conventional three times weekly HD (CHD) and 25 CVCs were exclusively used during NHD. The incidence and prevalence of CVC use in our NHD population was 35 and 25%, respectively. Comparing CHD to NHD, no significant differences were seen in total rates of infection, thrombolytic administration, or access-related hospitalization. Catheter survival was superior in NHD vs CHD (P=0.03). Adverse terminal catheter events were higher during CHD than NHD (5.84 vs 2.92/1000 CVCD; P=0.03). CVC use and complications in NHD is comparable to that in CHD with the benefit of longer cumulative survival. More frequent CVC use should not be a deterrent to NHD.

Clinical epidemiology of cardiovascular disease in chronic kidney disease

Cardiovascular disease (CVD) is the most common cause of death in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). The clinical epidemiology of CVD in CKD is challenging due to a prior lack of standardized definitions of CKD, inconsistent measures of renal function, and possible alternative effects of 'traditional' CVD risk factors in patients with CKD. These challenges add to the complexity of the role of renal impairment as the cause or the consequence of cardiovascular disease. The goal of this review is to summarize the current evidence on: (1) the incidence and prevalence of CVD in chronic renal insufficiency and in ESRD, (2) risk factors for CVD in CKD, (3) the outcomes of patients with renal failure with CVD, and (4) CKD as a risk factor for CVD. The epidemiological associations implicating the huge burden of CVD throughout all stages of CKD highlight the need to better understand and implement adequate screening, and diagnostic and treatment strategies.

The accuracy and interobserver agreement in detecting the 'gallop sounds' by cardiac auscultation

STUDY OBJECTIVES

To determine the observer accuracy and interobserver agreement in identifying S4 and S3 by cardiac auscultation and whether they improve with increasing observer experience.

DESIGN

Prospective, blinded study.

SETTING

Cardiology and general internal medicine wards in a university-affiliated teaching hospital.

PATIENTS

Forty patients with a cardiac diagnosis and 6 patients without were studied.

MEASUREMENTS AND RESULTS

Two cardiologists, one general internist, three senior and two junior postgraduate internal medicine trainees, blinded to the patients' characteristics, examined the patients and documented their findings on a questionnaire. Computerized phonocardiogram was obtained in all patients as a gold standard and was interpreted by a blinded, independent cardiologist. The mean positive predictive values for S4 and S3 were 51% (range, 24 to 100%) and 71% (range, 50 to 88%), respectively. The mean negative predictive values for S4 and S3 were 82% (range, 67 to 94%) and 64% (range, 56 to 85%), respectively. The overall interobserver agreements for detecting S4 was K = 0.05 (95% confidence interval [CI], 0.01 to 0.09) and S3 was K = 0.18 (95% CI, 0.13 to 0.24). There was no apparent trend in the accuracy or interobserver agreement with regard to the level of observer experience.

CONCLUSION

The agreement between observers and the phonocardiographic gold standard in the correct identification of S4 and S3 was poor and the lack of agreement did not appear to be a function of the experience of the observers. The overall interobserver agreement for the detection of either S4 or S3 was little better than chance alone.