Pattern and outcome of renal admissions at the University of Port Harcourt Teaching Hospital, Nigeria: A 4 years review.

BACKGROUND/
OBJECTIVE: Renal diseases constitute an enormous health burden globally, more so in developing countries. This report determines the patterns and outcomes of renal diseases in the medical wards of the University Teaching Hospital in Nigeria.
METHODS: A retrospective study of patients admitted for renal disease in 4 years.
RESULTS: A total of 3841 patients were admitted to the medical wards, of which 590 (15.4%) had renal disease. Mean age of patients was 46 ± 15 years. Median duration of admission was 14 days (range 1-92 days). The most prevalent renal diseases were hypertensive nephropathy, diabetic nephropathy, chronic glomerulonephritis, and HIV-related renal disease constituting 22.8%, 16.6%, 14.4%, and 13.1%, respectively. Acute kidney injury constituted 12.4% of renal admissions. Analysis of outcome showed that 317 (53.7%) were discharged home, 49 (8.3%) patients discharged themselves against medical advice or absconded while 120 (20.3%) patients died of the disease. The highest mortality rate (22.5%) was observed among patients with the HIV-related renal disease.
CONCLUSION: Renal disease remains a significant cause of morbidity and mortality in Port Harcourt, Southern Nigeria. This underscores an urgent need to institute measures for prevention and early detection of renal disease and reduction of its burden.

Introduction

The pattern of medical admissions in different regions of the world varies, and in developing countries such as in Nigeria, a trend toward noncommunicable diseases (NCDs) has been documented to account for a significant percentage of medical admissions.[12] This is in line with the prediction by the World Health Organization, which suggests that by 2030, the causes of disease and death in Sub-Saharan Africa (SSA) will have undergone a shift away from communicable and infectious diseases to NCDs.[3]

Kidney disease, particularly chronic kidney disease (CKD) plays a key role in determining health outcomes among the major NCDs, particularly diabetes and cardiovascular disease[4] and thus, has become a major public health concern worldwide rising as an NCD burden,[5] further adding to the burden of chronic medical disorders in hospitals.

In the Unites States, 10% of adults amounting to >20 million people are reported to have CKD with diabetes mellitus and hypertension being the leading causes of end-stage renal disease (ESRD).[6] In Nigeria and most Sub-Saharan African countries, population-based data of CKD are not common. Most of the data are hospital based. Earlier studies in Nigeria reported that CKD accounted for 8–10% of hospital admissions,[7] and in a Tertiary Hospital in South-East Nigeria, ESRD accounted for 7.96% of all medical admissions and 41.69% of renal admissions.[8]

In SSA, hypertension and glomerular diseases are common causes of CKD with an increasing prevalence of diabetic nephropathy as a cause of ESRD ranging from 6% to 16%.[9] A similar pattern has been observed in Nigeria where chronic glomerulonephritis (CGN), hypertension, and diabetes are the most common causes of CKD.[7810] Communicable diseases, particularly HIV infection is also thought to contribute to the burden of CKD in SSA.[5] The etiology of renal disease in HIV-infected persons is multi-factorial and includes the direct effect of the virus, presence of co-morbidities, and side effects of anti-retroviral drugs.[11]

Acute kidney injury (AKI), predominantly community-acquired type, is also an increasing cause of hospitalization with a high morbidity and mortality in this environment.[121314]

The aim of this study was to determine the pattern and outcome of renal diseases in patients admitted to the medical wards of the University of Port Harcourt Teaching hospital (UPTH), Nigeria, over a 4 years period (January 2010–December 2013).

Methods

This was a retrospective study conducted at the UPTH from data generated between January 2010 and December 2013. The UPTH is one of the major tertiary institutions in the oil-rich Niger Delta Region of Nigeria and serves as a referral center for Rivers state and neighboring Niger Delta regional states of Nigeria as well as some neighboring South-Eastern states. Patients are admitted to the medical wards via the Accident and Emergency Department, the medical out-patient clinics and the renal clinic.

Admission and discharge records were retrieved from the medical register in the medical wards. Information retrieved included age, sex, clinical diagnosis, date of admission, duration of hospital stay, and outcomes of treatment. The clinical outcome variables were discharged following improvement, absconded or discharged against medical advice, referral to another health facility and death.

Approval for the study was obtained from the Hospitals Research Ethics Committee.

Statistics

Collated data were analyzed using Statistical Package for Social Sciences version 17 (SPSS version 17, Chicago: SPSS Inc). Continuous variables were expressed as median or mean ± standard deviation while categorical variables were expressed as frequencies and percentages. The Student's t-test was used to compare continuous variables. Nonparametric tests as appropriate were used for data not normally distributed. A P < 0.05 was considered statistically significant.

Results

During the study period of 4 years (January 2010–December 2013), a total of 3841 patients were admitted to the medical wards of the hospital. Males constituted 2004 (52.2%), and females were 1837 (47.8%). The annual gender distribution of patients is shown in Figure 1.

Figure 1

Annual gender distribution of total medical admissions over the 4 years review period

Renal diseases accounted for 590 (15.4%) of total medical admissions in the ward. The annual renal admission trend is shown in Figure 2.

Figure 2

Annual renal admissions trend from January 2010 to December 2013

The mean age of patients with renal disease was 46 ± 15 years with a range of 17–85 years. The male patients were older, but this was not significant (47 ± 15 vs. 44 ± 16 years, P = 0.05). Figure 3 shows the age distribution of the patients with the peak group in the 30–39 years age group constituting 23%. The bulk of the patients were in the 30–39, 40–49, and 50–59 years age groups, respectively, constituting 60.2% of all patients.

Figure 3

Age distribution of renal patients

The median duration of admission for renal patients was 14 days (range 1–92 days). No significant statistical difference was observed in the median duration of admission between males (14 days, range 1–92 days) and females (14 days, range 1–77 days); P = 0.332.

The distribution of the patients in accordance with the underlying renal disease is shown in Figure 4. The five leading causes were hypertensive nephropathy in 134 (22.8%), diabetic nephropathy in 98 (16.6%), CGN in 85 (14.4%), HIV-related renal disease in 77 (13.1%), and AKI in 73 (12.4%) patients, respectively.

Figure 4

Pattern of renal diseases during the 4 years review period

Over this review period, 120 deaths were recorded, corresponding to 20.3% mortality rate, 76 (63.3%) of the demised were males and 44 (36.7%) females (P = 0.001). A total of 317 (53.3%) of patients were discharged following clinical improvement, and 49 (8.3%) discharged themselves against medical advice or absconded [Figure 5]. No outcome was indicated in ward records for 103 (17.5%) patients.

Figure 5

Outcome of renal admissions

The highest mortality, 22.5%, was seen in patients with the HIV-related renal disease while patients presenting with nephrotic syndrome accounted for 4.2% of mortality. Patients with renal disease of unknown etiology had a mortality of 15% [Figure 6]. Logistic regression showed a significant negative relationship between the duration of hospital stay and mortality, with a shorter admission duration being associated with increased mortality (B = −0.029, P = 0.005).

Figure 6

Pattern of outcome of mortality based on clinical diagnosis among patients

Discussion

This study aimed to determine the patterns of renal disease in patients admitted to the medical wards of UPTH over a 4 years period.

The peak age prevalence of patients admitted over this period was between the fourth and sixth decades, similar to previous studies in Nigeria.[1516] These are patients in the economically active age group, and this could be telling on the nation's economy. In contrast, in the United States, the Third National Health and Nutrition Examination Survey reports that CKD is more prevalent in adults over 60 years (39.4%) than in those aged 40–59 years (12.6%) and 20–39 years (8.5%).[17]

This study documented that renal diseases accounted for 15.4% of all medical admissions over the 4 years review period. In tropical countries, it is estimated that 2–3% of medical admissions are due to renal-related complaints.[18] Agomuoh and Unachukwu,[1] in an earlier study in Port Harcourt, reported that renal disease accounted for 16.8% of medical admissions. In South-West Nigeria, a lower prevalence rate of 6.5% of medical cases over a 3 years period were also due to renal disease in Oshogbo[19] while, in Ekiti State, Ogunmola and Oladosu[2] reported a prevalence of 7.2% over 2 years. The total number of medical admissions in this study was observed to gradually reduce in the last 2 years in review, though the percentage of renal cases remained between 11.6% and 18.2%. This high prevalence underscores the measure of the burden CKD places on the health care system in Nigeria. The median duration of hospital stay observed among the patients was 17 days with a range of 1–92 days. The majority of patients in Nigeria are self-funded or are funded by relatives, and prolonged hospital stay puts increased financial strain on families, in an economy that is already fraught with poverty and austerity.

The most common causes of renal diseases admitted were hypertensive nephropathy, diabetic nephropathy, and CGN. In Nigeria, studies report CGN leading as the most common cause of CKD followed by hypertension and diabetes.[720] This study reports hypertension and diabetes ranking above CGN with the possibility that the prevalence of CGN may be higher owing to the fact that up to 13.4% of the patients had CKD from unidentified causes. Other recent studies in Nigeria have shown hypertension overtaking CGN as a cause of CKD similar to this study.[821] Hypertension in blacks is said to occur earlier with its consequences of target organ damage including renal disease being more pronounced.[2223] Hypertension is also reported to be the leading cause of CKD in SSA.[9] In a rural South Africa community, hypertension accounted for 77.8% of patients with renal disease,[24] and in North Africa, reports from nephrologists puts the prevalence of hypertensive nephrosclerosis at 10–35%.[25] In contrast to this preeminence of hypertension as a cause of renal disease in Africa, diabetes mellitus is identified across other regions of the world as the leading cause of CKD and ESRD.[26] With Nigeria reported to have the largest number of people in Africa living with type 2 diabetes[27] and type 2 diabetes increasingly becoming a leading cause of CKD and ESRD in Nigeria,[28] we may be observing the earliest trends of an emerging CKD epidemic in this local setting despite the inherent shortcomings of being a retrospective and single-hospital study.

In this study, AKI accounted for 12.4% of admissions with a mortality of 12.5%. A meta-analysis of worldwide incidence of AKI reported an incidence rate of 21.6% in adults and a mortality rate of 23.9% with the highest rates observed in critical care settings.[29] AKI is also known to be associated with high morbidity and mortality despite enormous improvements in knowledge, skills, and available technology; this is particularly so in developing countries with resource-poor settings, such as shown by several studies in Nigeria.[121314]

This study showed a 13.1% prevalence of renal disease in HIV-infected patients. Nephropathy is common in HIV-infected patients, and Emem et al.[30] reported a high prevalence (38%) of renal disease in HIV patients in Nigeria. The highest mortality in this study was seen in patients with HIV infection. Kidney disease remains a significant cause of morbidity and mortality in this group of patients even in those receiving antiretroviral drugs, and the reasons for this high mortality are multi-factorial. It may be due to the fact that HIV-associated nephropathy is thought to follow a more severe course in blacks with rapid progression to ESRD.[31] AKI is also prevalent in patients with HIV infection, increasing the mortality in them. In this subgroup, the clinical outcome may be compounded by the presence of multiple co-morbidities as well as the side effects of anti-retroviral drugs.[11] Studies among medical admissions in Nigeria have also reported high mortality rates in patients with HIV infection.[3233]

The overall mortality rate of 20.3% was high in this study, and 8.3% of patients discharged themselves against medical advice or absconded from the hospital. Studies have identified reasons that patients may choose to go home against medical advice, and these include financial constraints, unsatisfactory clinical improvement, the desire to seek alternative or complimentary treatment, poor communication between patients and health care providers among others reasons.[3435] Logistic regression analysis in this study showed a that a shorter duration of admission was related to mortality, and this may suggest late presentations to the hospital in this group of patients with likely advanced stages of illness and hence a worse outcome. The clinical outcome in 17.5% of patients was not indicated in records underscoring the need for adequate record keeping in this environment.

This study is not without its limitations. Records in the hospital are kept manually; as a result, some books were torn and mutilated with resultant lack of some vital information in the records. Furthermore, changes which may have been made in patient diagnosis following further laboratory investigations may not be reflected in final diagnosis.

Conclusion

Renal disease is highly prevalent and accounts for a significant proportion of medical admissions in Port Harcourt, Nigeria. Hypertension, diabetes, and CGN remain the most common causes of CKD with diabetic renal disease gaining ground over CGN and with HIV becoming a significant cause of renal disease. The mortality in renal disease is high and more so in patients with HIV infection. Health education must be reinforced through various media with emphasis on lifestyle modification in addition to population screening exercises to detect major cardiovascular risk factors such as diabetes and hypertension and thus prevent and reduce the burden of kidney disease in Nigeria.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.