Cost per episode of diarrhea and respiratory syncytial virus (RSV) in 128 low- and middle-income countries: how well do disease-specific and WHO-CHOICE estimates align?

OBJECTIVE

Non-disease-specific WHO-CHOICE unit costs are often used in cost and cost-effectiveness studies in the absence of country-specific data. This study aims to compare reported country-specific disease costs and the corresponding WHO-CHOICE estimates. We use generically defined "diarrhea" (including rotavirus diarrhea) and pathogen-specific "respiratory syncytial virus (RSV)" disease as examples.

METHODS

We updated systematic reviews for both diseases in low-income (LICs), lower-middle-income (LMICs) and upper-middle-income (UMICs) countries. Diarrheal (including a sub-analysis of rotavirus-specific) and RSV-specific outpatient and inpatient costs per episode were extracted and compared with WHO-CHOICE estimates in the same countries. If a consistent pattern of under- or over-estimation was identified, we quantified the magnitude of the discrepancy. All costs were updated to 2022 international dollar values.

RESULTS

Out of 1975 new records identified, 23 new cost studies were included. Including previous reviews, we retained 31 diarrhea and 16 RSV studies for comparison. WHO-CHOICE based direct medical costs were similar for diarrheal disease including rotavirus diarrhea, but lower for RSV-related disease. We estimated the cost per episode of diarrhea and RSV in 128 countries. RSV outpatient cost were adjusted by multiplying WHO-CHOICE costs by 6.89 (95% uncertainty interval: 5.58-8.58) in LICs and LMICs and 5.87 (4.95-6.96) in UMICs; RSV inpatient costs were multiplied by 1.43 (1.01-2.01) and 1.36 (0.82-2.27), respectively.

CONCLUSION

WHO-CHOICE based costs should be used cautiously. They aligned well with studies for diarrheal disease, but underestimate costs of RSV-related disease. More country- and disease-specific cost data are needed, especially for RSV in LICs.