Critical care nursing service costs: Comparison of the top‐down versus bottom‐up micro‐costing approach in Brazil

Aim To estimate the nursing service costs using a top‐down micro‐costing approach and to compare it with a bottom‐up micro‐costing approach. Background Accurate data of nursing cost can contribute to reliable resource management. Method We employed a retrospective cohort design in an adult intensive care unit in São Paulo. A total of 286 patient records were included. Micro‐costing analysis was conducted in two stages: a top‐down approach, whereby nursing costs were allocated to patients through apportionment, and a bottom‐up approach, considering actual nursing care hours estimated by the Nursing Activities Score (NAS). Results The total mean cost by the top‐down approach was US$1,640.4 ± 1,484.2/patient. The bottom‐up approach based on a total mean NAS of 833 ± 776 points (equivalent to 200 ± 86 hr of nursing care) yielded a mean cost of US$1,487.2 ± 1,385.7/patient. In the 268 patients for whom the top‐down approach estimated higher costs than the bottom‐up approach, the total cost discrepancy was US$4,427.3, while for those costed higher based on NAS, the total discrepancy was US$436.9. The top‐down methodology overestimated costs for patients requiring lower intensity of care, while it underestimated costs for patients requiring higher intensity of care (NAS >100). Conclusions The top‐down approach may yield higher estimated ICU costs compared with a NAS‐based bottom‐up approach. Implications for nursing management These findings can contribute to an evidence‐based approach to budgeting through reliable costing methods based on actual nursing workload, and to efficient resource allocation and cost management.