Table 1.
Input parameters to model costs and benefits (per CBT participant)
| Parameter | Value | Range | Sources/Reference |
|---|---|---|---|
| Benefit 1: Decreased incidence of HIV | $41 | $39 to $43 | See Table 2 and Table 3 |
| Efficacy of alcohol intervention: | |||
| Percentage of patients reporting abstinence at 90 day follow-up (CBT intervention) | 69% | [54] | |
| Percentage of patients reporting abstinence at 90 day follow-up (Usual Care) | 38% | [54] | |
| Difference between intervention and usual care in percentage of patients reporting abstinence at 90 day follow-up (parameter 1.1) | 31% | 21% to 41% | |
| Percentage of HIV incidence attributable to alcohol consumption (parameter 1.2) | 13% | 1.8 to 16.5% | [86] |
| Consumer Price Index/Inflation Rates: | |||
| Average 2009 Kenyan CPI | 100 | [60] | |
| Average 2010 Kenyan CPI | 106.265 | ||
| Average 2011 Kenyan CPI | 121.17 | ||
| Average 2013 Kenyan CPI | 140.103 | ||
| Costs of treating new case of HIV: | |||
| Average non-drug related costs (2009 USD) | |||
| Lab tests | 32 | 29.2 to 36.2 | [66] |
| Visits | 24 | 18.8 to 29.2 | |
| Support services | 0.4 | 0.10 to 0.90 | |
| Fixed costs | 32 | 22.4 to 46.6 | |
| Sum of mean non-drug related costs (2013 USD) | 124 | [66] | |
| Median drug costs in USD: | |||
| 12 Month tenofovir/3TC/EFV drug regimen (2013 price) | 145.47 | 145.47–280.72 | [68] |
| Benefit 2: Increased Productivity | |||
| Labor Force Participation: | |||
| Average Monthly Min Wages (parameter 2.4 for LFP hours), USD (KES) | 76.93 (6503) | 57.42 to 103.60 (4854 to 8757) | [87] |
| Percentage rise in weekly hours worked after ARV treatment (LFP hours for parameter 2.3) | 19% | 3.7% to 34% (Normal Distribution, SE = 1.88, Mean = 4.6, Baseline total hours = 24.3) | [74] |
| Household Productivity: | |||
| Increase in female hours spent collecting parameter in past week: (HP hours for parameter 2.3) | |||
| Firewood | 1.056 | 0.15 to 1.96 (Normal distribution, SE = 0.461) | [78] |
| Water | 1.945 | 0.86 to 3.03 (Normal distribution, SE = 0.556) | [78] |
| Average Hourly Min Wage for House Worker (parameter 2.4 for HP hours), USD (KES) | 0.85 (72) | 0.58 to 1.03 (49–87) | [87] |
| Increase in ARV adherence due to increased abstinence: | |||
| Hazardous Drinkers (number of patients non-adherent/exposed) | 27.54% (19/69) | [7] | |
| Non-Drinkers (number of patients non-adherent/exposed) | 7.78% (112/1439) | [7] | |
| Increase in the likelihood that an HIV+ patient which moves from non-abstinence to abstinence behavior will be ARV-adherent (parameter 2.2) | 19.75% | 14.75% to 24.75% | Calculated from above values |
| Currency Exchange (1USD: KES) | 84.53 | [61] | |
Abbreviations: ARV antiretroviral, CBT cognitive behavioral therapy, CPI consumer price index, KNBS Kenya National Bureau of Statistics, 3TC lamivudine, EFV efavirenz, GPRM Global Price Reporting Mechanism, KES Kenyan shillings, USD US dollars, SE standard error
Range refers to the min-max interval used for sensitivity analysis