Sample size estimates are critical to the planning and interpretation of clinical studies, whether they are descriptive or analytical. Too small a sample size will result in imprecise estimates in a descriptive study and failure to achieve 'statistical significance' in an analytic or comparative study. Here we discuss what both researchers and readers should understand about the reasons for sample size estimates, how they are done and how achieving or not achieving the desired sample size can affect the interpretation of the outcomes.

Background

In Tanzania, there is no national trauma registry. The World Health Organization (WHO) has developed a data set for injury that specifies the variables necessary for documenting the burden of injury and patient-related clinical processes. As a first step in developing and implementing a national Trauma Registry, we determined how well hospitals currently capture the variables that are specified in the WHO injury set.

Methods

This was a prospective, observational cross-sectional study of all trauma patients conducted in the Emergency Units of five regional referral hospitals in Tanzania from February 2018 to July 2018. Research assistants observed the provision of clinical care in the EU for all patients, and documented performed assessment, clinical interventions and final disposition. Research assistants used a purposefully designed case report form to audit the injury variable capture rate, and to review Ministry of Health (MoH) issued facility Register book recording the documentation of variables. We present descriptive statistics for hospital characteristics, patient volume, facility infrastructure, and capture rate of trauma variables.

Results

During the study period, 2891 (9.3%) patients presented with trauma-related complaints, 70.7% were male. Overall, the capture rate of all variables was 33.6%. Documentation was most complete for demographics 71.6%, while initial clinical condition, and details of injury were documented in 20.5 and 20.8% respectively. There was no documentation for the care prior to Emergency Unit arrival in all hospitals. 1430 (49.5%) of all trauma-related visits seen were documented in the facility Health Management Information System register submitted to the MoH. Among the cases reported in the register book, the date of EU care was correctly documented in 77% cases, age 43.6%, diagnosis 66.7%, and outcome in 38.9% cases. Among the observed procedures, initial clinical condition (28.7%), interventions at Emergency Unit (52.1%), investigations (49.0%), and disposition (62.9%) were documented in the clinical charts.

Conclusions

In the regional hospitals of Tanzania, there is inadequate documentation of the minimum trauma variables specified in the WHO injury data set. Reasons for this are unclear, but will need to be addressed in order to improve documentation to inform a national injury registry.

Background

Renal failure carries high mortality even in high-resource countries. Little attention has been paid to renal failure patients presenting acutely in emergency care settings in low-to-middle income countries (LMIC). Our aim was to describe the profile, management strategies and outcome of renal failure patients presenting with indications for emergent dialysis to an urban Emergency Department (ED) in a tertiary public hospital in Tanzania.

Methods

This was a prospective cohort study of consecutive patients (age ≥ 15 yrs) presenting to the Emergency Medicine Department of Muhimbili National Hospital from September 2017 to February 2018. All patients with renal failure and complications requiring acute dialysis were included. A structured data collection sheet was used to gather demographics, clinical presentation, management strategies and outcomes. Data were summarized with descriptive statistics. Logistic regressions were performed to determine factors associated with receiving dialysis and with mortality.

Results

We enrolled 146 patients, median age was 49 years (IQR 32-66 years), and 110 (75.3%) were male. Shortness of breath 67 (45.9%) and reduced urine output 58 (39.7%) were the most common presenting complaints. The most common complications were hyperkalemia 77 (53%), uremic encephalopathy 66 (45%) and pulmonary edema 54 (37%). All patients were hospitalized, and 61 (42%) received dialysis. Overall mortality was 39% (57 patients); the mortality in non-dialysed patients was 53% vs. 20% (p < 0.0005) in those receiving dialysis. 54% of patients with health insurance were dialyzed, compared to 39% who paid out of pocket (adjusted OR = 0.3, 95%CI: 0.1-0.9). Patients (≥55 years) were less likely to be dialysed (adjusted OR = 0.2 [0.1-0.9]). Independent predictors of mortality were vomiting (OR = 6.2, 95%CI: 1.8-22.2), oliguria (OR = 3.4, 95%CI: 1.2-9.5), pulmonary edema (OR = 4.6, 95%CI: 1.6-14.3), creatinine level > 1200umol/L (OR = 5.0 95%CI: 1.4-18.2), and not receiving dialysis (OR = 8.0, CI: 2.7-23.5). Female sex had a lower risk of dying (OR = 0.13, CI: 0.03-0.5).

Conclusions

In this ED in LIC, acute complications of renal failure created a need for ED stabilization and emergent dialysis. Overall in-hospital mortality was high; significantly higher in undialysed patients. Future studies in LICs should focus on identification of categories of patients that will do well with conservative therapy.