The Sierra Leone Ultrasound Rainbow4Africa Project (SLURP): an observational study of ultrasound effectiveness in developing countries

Diagnostic tools available in low-income countries are often really basic even if patients can be as sick as those of the richer countries. Point-of-care ultrasound could be a solution for this problem. We studied the impact of ultrasound at the Holy Spirit Hospital, Makeni, Sierra Leone.

This is a prospective, observational study on outpatients presenting at the HSH. We enrolled continually for 1 month 105 patients asked for ultrasound examination by the caring physician that had to indicate the differential diagnosis hypothesized, the confidence degree about these on a 5-point Likert scale, and the therapy before and after the US. The primary outcome was to measure the difference in the number of differential diagnoses. Secondary outcomes were the rate of new diagnoses, the confidence changes of the visiting physician, and the changes in prescribed therapy or management. Categorical variables were compared using the Chi-square test, and continuous ones using two-tailed Student’s test and Likert with the Wilcoxon rank-sum test.

194 differential diagnoses were formulated, with a mean of 1.85 (DS 0.87) diagnoses per patient. 89 (46%) were excluded on the basis of US, reducing the mean of differential diagnosis per patient to 1, 0 (p < 0.001). US also introduced 53 new diagnoses in 42 patients (mean 1.26; SD 0.54), raising the final differential diagnosis from 105 to 158 (+50.5%) that is 1.51 (DS 0.79) per patient. There is a statistically significant reduction (18.6%) in diagnoses per patient after having performed the ultrasound (p < 0.001). The certainty level increased (Wilcoxon rank-sum test: p < 0.001). We did not reach the statistical significance studying the changes in therapy and management because the subgroups for analysis were too small. Nonetheless, we saw interesting changes in drug prescription and referral rate before and after the US.

Ultrasound is feasible in low-income countries; with it diagnostic hypotheses were reduced and new unexpected diagnoses were introduced. Further studies are needed to explore other strong outcomes like mortality, length of stay in hospital, and money saved with the use of ultrasound in developing countries.