Abstract
Using preference weights from a community sample, items from the Addiction Severity Index (ASI) were converted into a quality of life index (QOLI) and used to compare the cost-effectiveness of five addiction treatment modalities for pregnant women.
Interviews using the time trade-off methodology were conducted with 143 members of Massachusetts local health planning boards to determine preference weights for different health states resulting from active addiction. A multi-attribute utility formula was used to convert these seven preference weighted scores into a single QOLI. To apply the QOLI, these preference weights were combined with the number of problem days reported in each ASI domain by a sample of 439 pregnant women in MA in five treatment modalities, 1992-1996.
Starting at 10 years with an addiction problem, board members indicated that they would give up between 0.83 and 3.96 years to avoid the problems in one domain caused by addiction. The average QOLI was 0.68 at intake but increased by 0.19 points by 6-month follow-up to 0.87. All five treatment groups showed notable improvement in their quality of life. Mean improvements ranged from a high of 0.23 QOLIs for clients who received both residential and outpatient treatment to a low of 0.16 for clients who received only detoxification. Treatment costs ranged from 10,187 dollars for residential and outpatient combined to 2535 dollars for detoxification only, with costs per QOLI ranging from 14,912 dollars to 44,291 dollars.
Although this QOLI could benefit from further refinement and development, it showed promise as a single outcome measure for CEAs in the chemical dependency field. This QOLI was sensitive enough to distinguish between the treatment groups, it correlated well with other outcome measures and can be easily converted from the ASI using spreadsheet software and a simple formula.