Table 1 Summary of previous reviews on ethnic differences in CKD progression and/or mortality

Cass et al

189

Explores the linkages between disadvantage, often accompanied by geographic isolation, and both the initiation of renal disease, and its progression to  end stage renal disease (ESRD).

Discussion paper

Indigenous, non-Indigenous Australians

Unclear

Primary renal disease, genetic factors, early development and socioeconomic factors might explain excess burden of renal disease in indigenous populations

Weiner et al. (2004), Hsu et al.(2003), Mehrotra et al. (2008), Newsome et al. (2006)

Powe et al

75

Summarizes work that has been done to understand the reasons for a higher burden of CKD in racial and ethnic minorities and indicates where more focus needs to be placed, thereby providing a framework for the goal of prevention of CKD and its progression in these high-risk groups

Non-systematic literature review

African-Americans, Native Americans, Hispanics, Caucasians

Unclear

Ethnic minorities make up a disproportionate share of the ESRD population in the United States. Reasons for this are multifactorial including a concentration of biologic-clinical, sociodemographic, and behavioural risk factors for CKD among certain racial and ethnic minorities. Behavioural factors including patient and provider interactions are not yet fully explored and may be central to the delivery of optimal care and prevention of ESRD in racial and ethnic minorities.

Norris et al

7

Commentary on Newsome et al. (2008) paper and considers key issues around CKD risk factors to better understand racial differences in rates of end stage renal disease

Review/ commentary on published paper

Caucasians, African-Americans, Asians, American Indians/Alaska Natives, and Hispanics

Unclear

Biological factors (e.g.: genes) and environmental influences are associated with CKD progression.

Newsome et al. (2006), Weiner et al. (2004), Hsu et al. (2003), Mehrotra et al. (2008)

Barbour et al.

5 (and additional 8 discussed)

Summarizes the available evidence on ethnic differences in the rates of CKD progression towards ESRD

Systematic review

Caucasians, African-Americans, Afro-Carribbeans, Hispanics

Studies that directly observe rates of GFR decline in CKD cohorts of different races

The available evidence to date does not conclusively support the hypothesis of ethnic differences in the rates of progression through all-cause CKD. There are few properly designed studies that address this issue, and several often-cited studies have some methodological shortcomings that make interpretation difficult.

Choi et al. (2009), Hsu et al. (2003), Peralta et al. (2006)

Crews et al.

33

Reviews studies exploring ethnic and socioeconomic disparities in CKD

Literature review

African-Americans, Caucasians

Studies on disparities of CKD

Geographic disparities in CKD prevalence, progression and treatment exist. CKD progression is more rapid for ethnic minority groups as compared to whites and may be largely, but not completely explained by genetic factors.

Van den Beukel et al. (2013), Derose et al. (2013), Kovesdy et al. (2013), Samuel et al. (2014)

Horowitz

Explores the ethnic disparities in the prevalence, treatment, risks and outcomes of hypertension in patients with CKD.

Discussion paper

Caucasians, Hispanics, African-Americans

 Unclear

Control of BP in patients at all stages of CKD remains suboptimal.

Hsu et al. (2005), Hebert et al. (1997); Hsu et al. (2006)

Harding et al

48

Discusses genetic and social determinants of CKD in African-Americans and the impact of late referrals from primary care physicians to nephrologists on CKD outcomes

Literature review

Caucasians, African Americans

Unclear

Several factors contribute to disparities in outcomes for African Americans compared to Caucasians, including genetic and social determinants, late referrals, poor care coordination, medication adherence, low recruitment in trials.

Jadawi et al

32

Assesses the difference in the prevalence and progression of diabetic nephropathy, and the development of ESRD  in people from three different ethnic groups with type 2 diabetes

Systematic review and meta-analysis

Caucasian, South Asian, African-Americans/Afro-Caribbeans

Studies comparing Caucasian, South Asian and African Caribbean, in whichever combination, in adult patients with T2DM and diabetic nephropathy

There was no significant link between ethnicity (South Asian, Caucasian and African Caribbean) and the prevalence of microalbuminuria; however, the pooled incidence rate ratio for ESRD in African Caribbean compared with Caucasian participants was significantly higher. Further research is needed to explore the potential non-albuminuric pathways of progression to ESRD

Earle et al., (2001), Koppiker et al. (1998), Ali et al. (2013), Mathur et al. (2018), Lewis et al. (2015)

Chen

10

Commentary on Crews et al. (2018) paper and considers confounders of the association between dietary acid load and CKD progression

Review/ commentary on published paper

Caucasians, African Americans

Unclear

Racial disparities in the relation between dietary acid load and risk of ESRD may be confounded by severity, control, duration of diabetes and hypertension, and antihypertensive medications.

Crews et al. (2018), Parsa et al. (2013)