Prevalence of abnormal kidney function, clinical characteristics and 90-days outcomes among patients admitted on medical wards of Masaka regional referral hospital

Abstract

Background: Kidney disease is associated with significant morbidity and mortality. In Uganda, majority of patients with kidney disease are referred to national referral hospitals with kidney failure. Although a lot has been documented about the burden of kidney disease at national referral facilities, there is scanty data regarding abnormal kidney function among patients admitted at Regional Referral Hospitals (RRH), lower health facilities in Uganda which are the first points of care for most patients in country and at which instituting first line care could prevent deterioration of kidney function. In this study we determined the prevalence of abnormal kidney function (decreased estimated glomerular filtration rate < 90 ml/minute /1.73m² and proteinuria of ≥1+ on spot urine dipstick), clinical characteristics and 90 days outcomes among patients admitted on medical wards of Masaka RRH. Methods: Between September 2020 to March 2021, a study was conducted among adult patients admitted on medical wards of Masaka RRH to determine the prevalence of abnormal kidney function, clinical characteristics, and 90-days outcomes among these patients. Patients were enrolled in the study if they met the following inclusion criteria: a) were ≥18 years of age, 2) provided written informed consent, 3) had phone contacts to help with follow up of patients. A questionnaire was administered to capture information about demographics and clinical characteristics of patients, a spot urine sample was collected to assess for proteinuria and a blood sample was collected to assess serum creatinine levels. Estimated glomerular filtration rate (eGFR) was calculated using chronic kidney disease epidemiology collaboration formula. Patients with abnormal kidney function were followed up after 90-days to determine their disease outcomes. All data was entered into Microsoft office excel database, then exported to STATA version 13 software package for analysis. Continuous and discrete variables were summarized into means with standard deviations, medians and interquartile ranges (IQR). Categorical variables were summarized into frequencies and percentages. Outcomes of interest included: all-cause mortality, development of chronic kidney disease (CKD) and no confirmed CKD. Results: A total of 717 patients admitted on medical wards were screened and 357 were enrolled in the study. The overall prevalence of abnormal kidney function was 32.8% (117/357), with 08 (2.2%) patients having proteinuria ≥ 1+ alone, 68 (19.1%) having decreased eGFR of < 90 mls/minute/1.73m² alone, and 41(11.5%) having both proteinuria of ≥ 1+ and decreased eGFR of < 90 mls/minute/1.73m². The median age of these 117 patients with abnormal kidney function was middle age at 52 (IQR 39-70) years and majority were males (54.7%). Sociodemographic characteristics of patients associated with abnormal kidney function determined using bivariate analysis included; male sex with a crude odds ratio [cOR] 1.14 confidence interval [CI] 0.73-1.78, age of 54.5 years standard deviation [SD] 19.4 cOR 1.02 CI 1.01-1.04 p<0.001, Cigarette Smoking with cOR 1.14 CI 0.65-1.98 and alcohol use with cOR 1.03 CI 0.66-1.62. Clinical characteristics associated with abnormal kidney determined using multivariate analysis included: Male sex with adjusted odds ratio [aOR] 1.74 CI 1.04-2.91 P=0.036, qSOFA score of 2 with aOR 2.64 CI 1.08-6.44 P=0.033, previous history of diarrhea or vomiting in past 3 months with aOR 2.28 CI 1.38-3.76 P= 0.001 and hypertension with aOR 3.10 CI 1.70-5.66 P=<0.001. Of the 117 patients with abnormal kidney function, 108 were followed up to 90-days. The 90 day’s mortality was 69.4% (75/108), and 13.0% (14/108) had progressed to CKD. Conclusions and recommendations: The prevalence of abnormal kidney function is high among patients admitted on the medical wards at Masaka RRH and abnormal kidney function is associated with for kidney hypertension, Male sex, qSOFA score of 2 and previous history of diarrhea or vomiting in past 3 months. Many patients with abnormal kidney function had adverse outcomes including death and progression to CKD. To reduce on these adverse outcomes, RRHs and lower-level health care facilities in Uganda may benefit from basic screening and management protocols for patients at risk or with abnormal kidney function.