An exploration of under-registration of chronic kidney disease stages 3–5 in Belgian general practices using logistic regression

Abstract

Background Early detection and treatment of chronic kidney disease (CKD) can prevent further deterioration and complications. Previous studies suggested that the diagnosis is often made when advanced renal failure occurs. The aims of this study were to describe the prevalence of unregistered CKD stages 3–5 in a Belgian General Practitioner population, to determine risk factors for under-registration and to investigate the diagnostic delay. Methods The analyses were carried out in the INTEGO database, a Flanders general practice-based morbidity registration network. The study used INTEGO data from the year 2018 for all patients ≥18 years old. CKD was defined as two consecutive eGFR laboratory measurements (eGFR <60 mL/min/1.73m2) at least three months apart during the baseline period. Registered CKD was characterised by a documented diagnosis of CKD (ICPC2 U99) during the ≥12-month lookback period before the first eGFR measurement and up to six months after the second eGFR in the EHR. The prevalence of unregistered CKD and the median time of diagnostic delay were estimated. Baseline characteristics were described. A multivariate cross-sectional logistic regression analysis was conducted to identify determinants of unregistered CKD. We estimated the odds ratios and their 95% confidence interval. Results Among included patients, there were 10 551 patients (5.5%) meeting the criteria of CKD. The prevalence of unregistered CKD was 68%. The mean diagnostic delay was 1.94 years (Standard deviation 0.93). Being a male, a concurrent diagnosis of diabetes, stroke, heart failure and hypertension, and more severe CKD (stages 3b, 4 and 5) independently increased the chance on registered CKD. Conclusion The proportion of patients who had no registered CKD code in the EHR was substantial. The differences between registered and unregistered patients make thinking about solutions to facilitate registration in the EHR imperative.

Association between non-registration of chronic kidney disease and mortality and cardiovascular outcome: a time-to-event analysis of retrospective primary care data

“…Our previous research showed that there were small differences between registered and non-registered patients at baseline. 15 Hypertension was more frequently present in the registered (64.4% of the registered population) compared with the non-registered (51.7% of the non-registered population). Similar results were found for type 2 diabetes (33.1%) of the registered compared with 28.2% of the non-registered).…”

“…We need to consider the effect of antihypertensive medication on this outcome, since 48% of the patients took an ACE-I or an ARB. 15 The beneficial effect of these drugs on cardiovascular events and all-cause mortality has been confirmed in the past. 37 Ettehad et al described that in patients with CKD, smaller risk reductions in cardiovascular events were seen as a result of antihypertensive medication than in patients without CKD.…”

“…Small differences were also noticeable in the use of ACE-inhibitor (ACE-I) or angiotensin receptor blocker (ARB) (52.6% among the registered compared with 46.3% of the non-registered). 15 However, these small differences do not seem to provide an adequate explanation for the difference in mortality, partly in view of the result that the non-registered group had no higher risk of CVD.…”

“…This study was conducted following on from previous work. 15 In that research, the prevalence of non-registered CKD, the diagnostic delay (time between abnormal eGFR and diagnosis) and the baseline characteristics of the non-registered patient group were examined in a Belgian GP population. The same study population was used.…”

“… 14 15 In addition, mainly patients with early-stage CKD (stage 3) remained without official diagnosis. 15 Although we know that patients with CKD are more at risk, the impact of not registering a diagnosis has not been investigated, neither on cardiovascular outcome nor on mortality. 4–6 …”