Chronic Kidney Disease (CKD) is a major public health problem associated with a significant burden of morbidity, mortality and increased health care costs. Early detection of CKD may help mitigate poor outcomes and reduce the high costs associated with renal replacement therapies. Accurate assessment of kidney function, also known as glomerular filtration rate (GFR), is an important part of CKD screening as it facilitates earlier diagnosis, staging, proper dosing of medications, and ultimately planning for renal replacement therapy [1]. By earlier referral to nephrology teams, a potential opportunity to attenuate CKD progression and manage complications is created [2]. GFR can be estimated (eGFR) in numerous ways, with one of the most common methods being the MDRD equation using variables of serum creatinine, age, sex, and race. Routine reporting of eGFR using the MDRD or the CKD-EPI study equation is now common in many countries and in most Canadian provinces, despite being validated only in certain populations [3].

The widespread use of automatic eGFR reporting has been shown to allow better detection of CKD in the general population [4–6], but has been associated with increased referrals to nephrologists and subsequently longer wait times [6–9]. Automatic eGFR reporting has also increased the number of inappropriate referrals to nephrologists [4]. Strategies to educate primary care clinicians in order to increase the proportion of appropriate referrals, including how to interpret eGFR’s and when to refer patients to nephrologists have been tried, but have had limited success [5].

The purpose of this study was to evaluate a multi-faceted public health campaign in Manitoba to improve the appropriateness of nephrology referrals after the implementation of province wide automatic eGFR reporting.

The implementation of automatic eGFR reporting in Manitoba led to an increased number of nephrology referrals in the province. This resulted in a modest increased wait time for non-urgent referrals, and a concerning trend for increasing wait times in urgent referrals. Our findings parallel those of other centers, where eGFR led to more referrals, especially with older patients [4, 7, 8]. The proportion of inappropriate consultations remained high at 62.7% after our multifaceted educational intervention for primary care practitioners.

To our knowledge, only one previous study by Phillips et al. has simultaneously studied the combination of nephrology referrals, appropriateness of consultations, and wait times in the context of automatic eGFR reporting [14]. This study was conducted in the United Kingdom, where a significant proportion of income for primary care physicians are linked to certain quality targets in CKD management. After eGFR reporting began, a similar rise in nephrology consultations was reported. Shortly after, a patient referral pathway to guide primary care physicians for appropriateness of referral was disseminated, and found to improve the appropriateness of consults. Canada differs from the UK system in that it does not tie financial reimbursement to quality targets in primary care, and therefore a similar strategy may not be as effective in attenuating inappropriate consult rates. We therefore attempted a more robust educational strategy including an analogous referral pathway as the Phillips et al. study.

Automatic eGFR reporting has led to more referrals in many studies, which in many cases has allowed the capture of more patients with CKD [15, 16]. Earlier identification of these patients by primary care clinicians allows for treatment to attenuate CKD progression to ESRD through interventions such as tight blood pressure control, renin-angiotensin system inhibitors, and consultation with a nephrologist [17–20]. The STAART study demonstrated that patients who have follow up for greater than one year by a nephrologist are more likely to have optimal dialysis starts with pre-emptively created fistulas, start on peritoneal dialysis, begin dialysis as elective outpatients, and have a lower mortality rates. However, the increased referral rates that have been seen with eGFR reporting have not paralleled a significant change in “appropriate nephrology consultations” or lessened the progression to end stage renal disease. This is likely due to the fact that the majority of the new referrals are at low risk of CKD progression to ESRD [4, 5, 9].

Improving front line providers knowledge and awareness of CKD is an essential element for effective, “appropriate”, risk based triage of referrals to nephrology [21]. Primary care clinicians have indicated a need for more education in areas of eGFR interpretation, clinical utility, and methods of conveying its meaning to patients [16, 22]. They have also expressed that they would like feedback on their current CKD care practices, when to refer to a specialist, established roles in clinical care before and after nephrology referrals, and regular updates on current guidelines of best practices [16, 23]. The need to provide support in these areas is reinforced by multiple studies, which have illustrated disparities in primary care clinicians CKD knowledge translation, recognition of CKD risk factors [24], interpretation of creatinine and eGFR measurements, diagnostic evaluation for CKD, and utilization of current management guidelines [25]. Our program employed a comprehensive public health strategy to encourage proper utilization of the eGFR tool by deriving referral pathways in collaboration between nephrologists and primary care physicians and using mass mail outs, didactic presentations, web-based videos, and dedicated web-based resources to disseminate knowledge on appropriate referrals. Despite these efforts, the numbers of inappropriate referrals remained high and wait times increased.

There are several clinical, research and public health implications to our findings. Clinical practice guidelines have been a popular strategy used to address gaps in CKD recognition and advise when to prompt a nephrology referral. Similar to our study however, practice guidelines have not been an effective solution to bridge these inconsistencies. Previous studies have described reasons why guidelines are ineffective in primary care, including provider lack of awareness and familiarity with guidelines, disagreement with recommendations, lack of confidence with self-efficacy or time to carry out recommendations, apprehension to change previous practices, and absence of external pressures to change practices [26]. In the case of nephrology, this problem is compounded by regional variation of guidelines [27, 28], the increasingly complexity of making a CKD diagnosis, the development of new equations such as CKD-EPI and cystatin C, and the incorporation of proteinuria with staging [29].

Recognition of high risk patients by simpler methods of interpretation, such as printed reports with statements reminding appropriate referral guidelines, or the KDIGO heatmap [30, 31], could incorporate these new variables into a more concise model that would be easier to apply in primary care. Computer decision support systems [32, 33] such as electronic medical records [25] or practice enhancement assistants [34] are potential promising solutions in increasing physician awareness and detection of CKD, decreasing duplication of tests, ease comparisons with prior results, and providing alerts when labs results return. It also has the ability to advise drug-dosing, interpretation of results, and provide referral suggestions. One additional benefit of computer support systems for patients, is that they can review their individual results from their own computers, potentially improving their interest and self-management of their own diseases [25]. A potential effective approach to improve practice patterns would be to audit current performances of primary care providers, then convey benchmarks or comparisons of certain indicators to them while reinforcing indications for an appropriate referral to nephrology [33]. This type of feedback on current performance has been shown in numerous quality improvement initiatives to improve CKD awareness and management, especially when combined with key opinion leaders messages’ [31].

A more robust and perhaps more effective strategy may be to intervene on the process of referral intake. Centralized, standard referral processes allows for a single triage area to receive, process, screen for appropriateness of the referral and completeness of the consultation, and to evenly distribute referrals. More urgent consults could be better triaged, completeness of referral information should be ensured to prevent secondary delays, and wait lists can be balanced for each nephrologist. Subspecialty nephrology clinics, such as glomerulonephritis, hypertension, CKD with pregnancy, or genetic disease clinics, can have referrals directed toward them more efficiently as well in a triage based system. Utilization of risk prediction equations [35] can also help prioritize the urgency and necessity for low risk patients to be seen by nephrology.

This study has several strengths, including a random sample of groups in the pre and post eGFR implementation periods for group comparisons of demographics and wait times. The MRP receives all nephrology referrals in the province allowing for virtually complete data capture of referred patients. Although our educational intervention was multi-faceted, one limitation of our study was that we did not measure how well primary care providers reviewed or grasped the content, which may have affected our appropriateness data. Another limitation in our time series design is that we provide 6 data points in the pre and post periods for number of referrals, which yielded a trend, but may have been statistically significant had we had increased power. We did not report race with our demographics, as this information was not available to us. However, Manitoba has a small African American population of less than 1.4% [36], so the calculated mean eGFR was unlikely to be largely influenced by this missing information. In addition, the retrospective nature of our study did not allow us to measure all key statistics that could influence our outcomes, making residual confounding of our results a possibility.

In conclusion, EGFR implementation has shown to be a useful tool in CKD screening, but with it has come challenges of increase nephrology referrals and longer wait times. In Manitoba, despite our significant efforts at a robust knowledge translation initiative we also encountered similar setbacks. A higher yield to improve the referral intake process would perhaps be to better align risk of CKD progression with resource utilization, which in turn may lead to a prospect for larger gains in improving the quality of care.