Table 4 Classification and types of calculation
From: Evaluating the costs of adverse drug events in hospitalized patients: a systematic review
Method of calculation | Nb of studies (%) | N° (Table 3) |
|---|---|---|
Studies directly calculating the cost of ADE | 15 (75) | 1, 4, 5, 6, 8, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20 |
Studies estimating the cost of ADE through external data or studies | 5 (25) | 2, 3, 7, 9, 16 |
Number of direct costs considered in the calculation: | ||
1 | 10 (50) | 2, 3, 5, 7, 8, 9, 14, 19, 20 |
2 | 1 (5) | 11 |
≥ 3 | 9 (45) | 1, 4, 6, 10, 12, 13, 15, 16, 17, 18 |
Only direct costs | 16 (80) | 1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17, 19, 20 |
+ indirect costs | 3 (15) | 5, 15, 18 |
+ opportunity costs | 1 (5) | 16 |
Micro-costing method Real costs of exact resources consumed in the care of each patient | 4 (20) | 1, 6, 12, 18 |
ADR vs. non-ADR method (propensity scores matching) Costs difference between ADR patients and matched control (non-ADR patient) | 3 (15) | 11, 18, 19 |
Gross-costing method Assign average values from national administrative databases | 2 (10) | 5, 13 |
Extended LOS attributable to preventable ADE method Extra medical costs = Hospital admission x number of patients with preventable ADEs × estimated extended LOS | 1 (5) | 3 |
Before vs. after ADR method Difference between the total medical care cost of a patient 6 months before the ER visit for an ADR and 6 months after Expenses for a new diagnosis of diseases (other than those diagnosed during the control period) were not included | 1 (5) | 10 |
Resource use method 1. ADE identification: manual from medical records, causality assessments between potential ADEs and drug therapies with causality levels (definite/likely/possible) 2. Resource use identification: contribution to healthcare use: assessment of each ADEs contribution to resource use, with contribution levels (dominant/partly/less) 3. Proportion of costs from regional cost per patient register: ADE contribution dominant = full costs ADE contributed partly or less = cost for specific resources used for ADEs | 1 (5) | 17 |
Proportion of registered costs method 1. ADE identification: manual from medical records, causality assessments between potential ADEs and drug therapies with causality levels (definite/likely/possible) 2. Resource use identification: contribution to healthcare use: assessment of each ADEs contribution to resource use, with contribution levels (dominant/partly/less) 3. Proportion of costs from regional cost per patient register: ADE contribution dominant = full costs ADE contributed partly = \(1 \!\left/ \! 2 \right.\) of costs ADE contributed less = \(1 \left/ 3 \right.\) of costs | 1 (5) | 17 |
Unit cost method 1. ADE identification: manual from medical records, causality assessments between potential ADEs and drug therapies with causality levels (definite/likely/possible) 2. Resource use identification: contribution to healthcare use: assessment of each ADEs contribution to resource use, with contribution levels (dominant/partly/less) 3. Proportion of costs from national statistics: ADE contribution dominant = full costs ADE contributed partly = \(1 \left/ 2 \right.\) of costs ADE contributed less = \(1 \left/ 3 \right.\) of costs | 1 (5) | 17 |
Diagnostic code method 1. ADE identification with ICD codes indicating ADEs 2. Resource use identification: all resource use during the healthcare encounter assigned to the ADE 3. Estimating cost with regional or national registers: full costs, \(1 \left/ 2 \right.\) costs, \(1 \left/ 3\right.\) costs | 1 (5) | 17 |
Main diagnosis method 1. ADE identification: manual matching with main diagnosis and ICD codes 2. Resource use identification: all resource use during the healthcare encounter assigned to the ADE 3. Estimating cost with regional or national registers: full costs, \(1 \left/ 2 \right.\) costs, \(1 \left/ 3\right.\) costs | 1 (5) | 17 |