Table VII.

Quality of studies as defined by Drummond criteria

Drummond criteria	Chun et al., 2016	Chowers et al., 2015	Bessesen et al., 2013	Hassan et al., 2007	Montecalvo et al., 2001	van Rijen et al., 2009	Wassenberg et al., 2011
1. Clarity of the question being asked	High	High	High	High	High	High	High
2. Comprehensive description of the competing alternatives	Moderate	High	High	Low	Low	Low	High
3. How the programme's effectiveness was assessed	High	High	High	Moderate	Moderate	High	Moderate
4. Identification of costs and consequences of each alternative being compared	High	High	High	Moderate	High	High	Moderate
5. Accurate measurement of costs and consequences using appropriate physical units	High	High	High	Moderate	High	High	Moderate
6. Credibility of the assessment of costs and consequences	High	High	High	Moderate	Moderate	High	Moderate
7. Costs adjusted based on timing: discounting	Low	Low	Low	Low	Low	Low	Low
8. Differential analysis of costs and consequences of competing alternatives	Moderate	Moderate	High	Moderate	Moderate	High	Moderate
9. Allowance made for uncertainty in estimates of costs and consequences: sensibility analysis	High	High	Low	Low	Low	Moderate	Low
10. Clarity of the presentation and discussion of the results: comparison of results against those of other studies and in other jurisdictions	High	High	High	High	Moderate	High	High
Overall assessment
High	7 (70.0%)	8 (80.0%)	8 (80.0%)	2 (20.0%)	3 (30.0%)	7 (70.0%)	3 (30.0%)
Moderate	2 (20.0%)	1 (10.0%)	0 (0.0%)	5 (50.0%)	4 (40.0%)	1 (10.0%)	5 (50.0%)
Low	1 (10.0%)	1 (10.0%)	2 (20.0%)	3 (30.0%)	3 (30.0%)	2 (20.0%)	2 (20.0%)