Table 3. Incremental Cost-Effectiveness Analyses: Cocaine Outcomesa.
| Incremental Costs | Incremental Effectsb | ICER (ΔC/ΔE, $) | |||||||||
| Δ Costs per participant | Occasions Usedc | Episodes per Dayd | Days Freee | Abstaining, past 30 daysf | Abstaining, past 4 monthsg | Cost per Occasion Avertedh | Cost per Episode Reducedi | Cost per Cocaine Free Dayh | Cost per Abstainer, past 30 days | Cost per Abstainer, past 4 months | |
| Treatment Groups | |||||||||||
| BL to 4 mo | |||||||||||
| SI | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| SI+WWE | $144.45 | −0.06 | 0.29 | −0.18 | 0.01 | 0.02 | D | $498.10 | D | $14,445.00 | $7,222.50 |
| SI+WWE+4ES | $942.30 | 6.44 | 0.27 | −0.67 | 0.05 | 0.05 | $146.32 | $3,490.00 | D | $18,846.00 | $18,846.00 |
| BL to 12 mo | |||||||||||
| SI | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| SI+WWE | $144.45 | 0.43 | −0.07 | −0.37 | 0 | 0.04 | ED | D | D | D | $3,611.25 |
| SI+WWE+4ES | $942.30 | 21.88 | 0.89 | 1.87 | −0.02 | −0.03 | $43.07 | $1,058.76 | $503.90 | D | D |
Abbreviations: SI, NIDA's Standard Intervention; WWE, SI plus Well Woman Exam; 4ES, SI, WWE plus four educational sessions; ICER, incremental cost effectiveness ratio, which is the difference in cost divided by the difference in effectiveness as compared with the next least costly intervention, and indicates cost per additional outcome achieved; BL, baseline; D, dominated, which indicates that the intervention is more costly and less effective than the alternative; ED, extended dominated, which indicates that the next alternative is more costly, more effective and has a better ICER.
Costs from Ruger et al., 2010. Due to rounding, calculations may not exactly reflect data from Table 2. ICERs did not need to be adjusted because the intervention has a sufficiently long follow up time period.
Positive number indicates incremental improvement. Each value is the difference of the differences from Table 2.
Number of occasions used cocaine, past 30 days (number of days used * times per day).
Number of episodes used cocaine per day, past 30 days.
Number of cocaine free days, past 30 days.
Proportion of participants abstaining from cocaine, past 30 days.
Proportion of participants abstaining from cocaine, past 4 months.
Past 30 days.
Per day, past 30 days.