acquisition is a lengthy and sometimes challenging process. However, it is laudable how generally able and willing investigators conducting CKD research in Africa have been to participate in this network. This shows the level of awareness of the devastating consequences of the disease among the African CKD research community and the desire to work collectively to address the problem. The process of data management is also a labour-intensive process. The data coding and transfer from original studies into the IPD database is done by a senior staff member, or by a student under supervision of a senior staff member of the central structure. During this process, participant characteristics and screening accuracy results for each study, using the cleaned datasets, are compared with those from the original datasets to identify any potential discrepancies. In addition to obtaining the original IPD, aggregate data are extracted from the published articles of included studies. At this point, cross-checks between the published data with the original IPD obtained from each dataset are conducted and any inconsistencies discussed with the original authors. It is crucial to record and update contact information as this will ease subsequent communication, which often occurred years after the first data request was sent. PROGRESS TO DATE As of 1 April 2021, through our scoping efforts, we had identified 108 researchers who were the principal investigators (PIs) of 120 potential studies. Of these, 92 PIs were contacted to gauge their interest in collaborating in the consortium, as 16 PIs had either no author contact information or incorrect contact details. Of the 92 PIs contacted, 36 consented to participate in the network, with the remaining 56 PIs being either non-responsive to our call or, in two cases, unwilling to participate in the network. The consenting studies span across 12 African countries with a total of 46276 participant-level data. To date, the network has successfully curated data from 39 studies conducted in 12 African countries, totalling 35747 participants. Most enrolled studies are from sub-Saharan Africa, with one study representing north Africa25 (figure 1). Of the included studies, the number of participants range between 300 and 2543 per study. Some studies are still undergoing enrolment, and therefore, the number of study participants continues to grow. Of the participating studies (table 1), data collection of 14 studies (36%) took place before 2010,25–38 with the remaining 64% sampled between 2010 and 2017. Four of the participating studies have not been published yet. Overall, 79% of the IPD are from studies in the general population,28 30–34 36 37 39–50 7% are from studies of people with HIV-infection,27 29 51–54 6% from studies of populations with hypertension35 55 56 and 4% consists of people with diabetes mellitus57 (figure 2). The final 4% of the IPD constitutes two studies in patients with kidney failure26 58 and one study conducted in first-degree relatives of people with CKD.25 Of the 25 studies conducted in general populations, 88% (n=22) are geographically defined cohorts, with two of the remaining studies conducted among teachers recruited from primary, secondary and intermediate public schools30 39 and one study (not yet published) conducted in undergraduate students. The participants in the high-risk subpopulations were recruited from outpatient diabetes, hypertension and HIV clinics. Most studies included adults in a broad age range, with the included cohorts comprising adults between the ages of 18 –100 years. One unpublished study from Nigeria included only undergraduate students and therefore selected individuals in the age range 18–30 years. All studies recruited both male and female participants, with most having greater female participation. All, except one study used serum creatinine to estimate GFR and characterise CKD, with 76% additionally determining the presence of albuminuria or proteinuria. Only one study satisfied the 3-month chronicity criterion for diagnosing CKD.56 All the studies include participants with normal kidney function and mild-to-severe stages of CKD (CKD stages 1–4), with 32% not having participants in the most severe stage of kidney failure (stage 5 CKD). All included studies used standardised creatinine assays, with the Jaffe method59 being the most commonly used method for determining serum creatinine concentration. Three of the 38 studies44 48 50 used enzymatic methods to determine serum creatinine concentrations. All studies have data on Figure 1 Distribution of African countries enrolled in the CKD-Africa Collaboration. The individual participant data (IPD) ranges from 300 participants to 12247 participants per country. The nine shaded countries represent those for which IPD are currently available. The shading from light blue to dark blue represents the increasing number of IPD available per country, thus, the darkest shading represents the countries with the most available IPD. CKD, chronic kidney disease. on July 8, 2022 by guest. Protected by copyright. http://gh.bmj.com/ BMJ Glob Health: first published as 10.1136/bmjgh-2021-006454 on 4 August 2021. Downloaded from George C, et al. BMJ Global Health 2021; 6:e006454. doi:10.1136/bmjgh-2021-006454 5 BMJ Global Health Table 1 Characteristics of participating studies in CKD-