Prevalence of Chronic Kidney Disease (CKD) and Risk Factors in Sub-Saharan Africa
Condition: Chronic Kidney Diseases; Diabetes Mellitus; Hypertension; Tuberculosis; Schistosomiasis; HIV Infections
MeSH terms: Tuberculosis; Schistosomiasis; Kidney Diseases; Renal Insufficiency, Chronic
Study type: Observational

Summary: 
      Prospective cross-sectional study at the outpatient clinic (OPC) of the Bagamoyo District
      Hospital (BDH) in Tanzania. Assessment of basic epidemiological data (Point prevalence and
      risk factors) on CKD with simple clinical, laboratory tests and the patients history. After
      informed consent blood samples are taken for complete blood count, serum creatinine, HbA1c,
      HIV-Screening, and urine samples for dipstick, urine sediment, and albumin-creatinine ratio.
      Further, office blood pressure, weight and height are taken. Further, patients history are
      asked by a questionnaire (i.e.history of infectious and cardiovascular diseases and basic
      demographic data: i.e. sex, age).

      CKD is defined as the presence of either impaired kidney function and/or albuminuria based on
      a one-time measurement.

      Primary outcome of the study are prevalence rates of CKD and the impact of non-communicable
      and communicable disorders on CKD.
    

Detailed description: 
      Study population and Setting:

      Single centre cross-sectional study at the outpatient clinic (OPC) of the Bagamoyo District
      Hospital (BDH) in Tanzania. The BDH is located in Bagamoyo township on the coast of the
      Indian Ocean and provides care for a semi-rural population. After informed consent, all
      patients ≥ 18 years, irrespective of the reason of consultation, are included. Pregnant women
      and patients who are not able or willing to provide an informed signed consent are excluded.

      Measurements and procedures:

      All data are collected in a case report form, translated from English to Swahili. In all
      participants body weight and height, blood pressure, heart rate and temperature are recorded.
      After informed consent, a blood sample is taken for complete blood count and serum
      creatinine. Complete blood count is performed by a Sysmex Xs 800i analyser. Serum creatinine
      is measured using Creatinine Jaffe Gen2 reagent on a Cobas Integra 400 plus analyser. HbA1c
      is measured from capillary blood by using a bed-side DCA 2000+ Analyzer (Siemens Healthcare
      Diagnostics). After informed consent, HIV-screening is done with an immunochromatographic
      test for antibodies to HIV-1 and HIV-2 (test kits: Uni-Gold TM HIV, Trinity Biotech, Ireland;
      Determine® HIV-1/2, Inverness Medical Japan, Japan; SD BIOLINE HIV-1/2 3.0, SD Standard
      Diagnostics, Korea).

      All participants are instructed to void a clean-urine specimen. Urine samples are prepared
      for microscopic analysis. Albumin-to- creatinine ratio (ACR) is measured using a DCA 2000+
      analyser (Siemens Healthcare Diagnostics). CKD is defined as the presence of either impaired
      kidney function and/or albuminuria based on a one-time measurement. When one-time
      measurements are used, prevalence of reduced glomerular filtration rate (GFR) and albuminuria
      might be overestimated due to physiological variation and temporarily elevated values after
      physical activity and during acute illness or dehydration. Nevertheless, one-time
      measurements have been used for screening and epidemiologic purposes, as longitudinal
      documentation is not usually available in epidemiological studies. Kidney function is
      assessed by eGFR using the CKD-EPI formula. CKD is defined as an eGFR of <60 ml/min/1.73m2
      and/or an ACR of ≥30mg/g (≥3 mg/mmol) and categorized according to Kidney Disease: Improving
      Global Outcomes (KDIGO) stages. Office BP is assessed by a single measurement using a manual
      sphygmomanometer in a sitting position after 5 minutes at rest. Systolic and diastolic BP is
      classified as normal (<120/<80 mmHg), pre-hypertensive (120-139/80-89 mmHg), hypertensive
      stage 1 (140-159/90-99 mmHg) or hypertensive stage 2 (≥160/≥100 mmHg) in analogy to the
      cut-off values of the JNC 7 report. Anaemia is defined as Hb <13.0 g/dl in male and <12.0
      g/dl in female patients. Diabetes mellitus is defined as a history of diabetes, the use of
      antidiabetic medication or a HbA1c of ≥ 6.5%.
    

Intervention name(s): estimated glomerular filtration rate and albuminuria
Intervention type(s): Diagnostic Test
Intervention description(s): chronic kidney disease according to KDIGO
Observational model: Cohort
Time perspective: Cross-Sectional
Sampling method: Probability Sample
Study population: 
        Single centre cross-sectional study at the outpatient clinic (OPC) of the Bagamoyo District
        Hospital (BDH) in Tanzania. The BDH is located in Bagamoyo township on the coast of the
        Indian Ocean and provides care for a semi-rural population. After informed consent, all
        patients ≥ 18 years, irrespective of the reason of consultation, were included. Pregnant
        women and patients who were not able or willing to provide an informed signed consent were
        excluded.
      
Keywords: chronic kidney disease; communicable disease; sub-Saharan Africa; Tanzania; neglected disease; prevalence; double burden