Table 1.
Descriptive Characteristics of Studies Included in Systematic Review of VTE Pharmacologic Prophylaxis after Total Hip and Knee Replacement
| Characteristic | Number of Studies (%)* |
|---|---|
| Setting | |
| USA | 14 (42) |
| Canada | 4 (12) |
| Europe | 14 (42) |
| South Africa | 1 (3) |
| Economic Perspective | |
| Institutional | 20 (61) |
| National health system | 10 (30) |
| Societal | 3 (9) |
| Sponsorship† | |
| Pharmaceutical sponsor | 10 (30) |
| Pharmaceutical grant | 9 (27) |
| Pharmaceutical consultants | 2 (6) |
| Government agency | 3 (9) |
| None reported | 9 (27) |
| Comparison Type | |
| Anticoagulant vs. aspirin | 2 (6) |
| LMWH‡ vs. warfarin | 15 (45) |
| Fondaparinux vs. LMWH | 10 (30) |
| Comparisons with new oral anticoagulants | 2 (6) |
| Extended vs. short duration prophylaxis | 9 (27) |
| Quality Inventory¶ | |
| Costs measured through primary source? | 16 (48) |
| Effectiveness calculated using pooled results of systematic review? | 6 (18) |
| Data sources comprehensively documented and credible? | 29 (88) |
| Costs and effects discounted (for studies with horizon 1 year or more)? | 6 (18) |
| Incremental cost-effectiveness ratio (ICER) calculated correctly? | 30 (91) |
| One-way sensitivity analysis used comprehensively? | 13 (39) |
| Other Distinguishing Features | |
| Effectiveness measured in QALYs at a horizon of at least one year? | 7 (21) |
| Asymptomatic VTE adequately addressed? | 18 (54) |
| Post thrombotic syndrome adequately addressed? | 10 (30) |
| Major Bleeding included in cost calculation? | 28 (85) |
Abbreviations: LMWH = low molecular weight heparin, VTE = venous thromboembolism, QALY = quality adjusted life-year,
*
Out of 33 studies.
†
If both pharmaceutical and government sponsorship, pharmaceutical sponsorship was recorded
‡
Low molecular weight heparin
¶
Derived from quality scales published separately by Drummond20 and Brauer21.