Cost, effects, and cost effectiveness of interventions are listed in tables 6 and 7 for sub-Saharan Africa and South East Asia and are rank ordered on the basis of their incremental cost effectiveness ratios (the tables do not include dominated interventions that are more costly or less effective than other interventions). The focus here is on determining the most efficient set of interventions, first within and then across the disease specific groups (costs, effects, and cost effectiveness of all interventions are listed in appendices 4–6 on bmj.com for cervical, colorectal and breast cancer respectively).
Table 6 Costs, effects, and cost effectiveness of interventions to combat breast, cervical, and colorectal cancer in WHO sub-Saharan African sub-region AfrE
Table 7 Costs, effects, and cost effectiveness of interventions to combat breast, cervical, and colorectal cancer in WHO South East Asian sub-region SearD
In both regions, certain interventions in cervical cancer control (that is, screening with smear testing or visual inspection with acetic acid in combination with treatment) and colorectal cancer control (increasing the coverage of treatment interventions) cost <$Int2000 per DALY averted and can thus be considered highly cost effective. In the African sub-region, screening for colorectal cancer (by colonoscopy at age 50 in combination with treatment) costs <$Int6000 per DALY averted and can be considered cost effective. In both regions, certain interventions in breast cancer control (treatment of all stages in combination with mammography screening) cost between $Int2000 and $Int6000 per DALY averted and can be considered cost effective. Below we discuss the findings in detail.
In breast cancer control, treatment of all stages in combination with mammography screening costs $Int2248–4596 per DALY averted in both regions. At an optimal coverage level of 95%, this optimal programme would avert 381 and 595 DALYs per million population in South East Asia and sub-Saharan Africa respectively, at a cost of between $Int1.38 and $Int1.68 per capita (that is, around US$0.45–0.55). In both regions treatment of stage I cancer costs between $Int3800 and $Int4548 per DALY averted, whereas treatment of stage IV costs >$Int49 000 per DALY averted and is the least cost effective option (these interventions are less effective or more costly than other combination in breast cancer control and are therefore not reported in tables 6 and 7).
For cervical cancer, screening 50% of the target population through a single smear test at age 40, with lesion removal and treatment as required, represents the single most cost effective strategy in both sub-Saharan Africa and South East Asia ($Int307 and $Int142 per DALY averted respectively). In both regions, the next most cost effective intervention is treatment of invasive cancer with an appropriate combination of surgery, chemotherapy, and radiotherapy. In both regions, screening by means of visual inspection with acetic acid instead of the smear test is slightly more effective but also more costly, and therefore less cost effective. In sub-Saharan Africa adding an HPV vaccination programme to the provision of smear tests at age 40 and treatment as required can be considered very cost effective if a cost per dose of US$0.60 can be realised. In the South East Asia, an HPV vaccination programme is not cost effective even at the same low vaccine price. Adding a booster vaccination every 10 years in addition to such strategies has a negligible impact on health outcomes but substantially increases costs and hence incremental cost effectiveness values.
In colorectal cancer control, the most cost effective strategy is the increased coverage of treatment interventions: at 95% coverage, this would avert 792 and 868 DALYs per million people in South East Asia and sub-Saharan Africa respectively, at a cost of around $Int0.30 per capita in both regions (that is, around US$0.10). Once treatment has been scaled up, it would still be cost effective to introduce colonoscopy screening at age 50 in sub-Saharan Africa. The incremental cost and cost effectiveness of all other assessed interventions makes them much less attractive options.
The incremental cost and cost effectiveness of these interventions are shown in figures 1 and 2, which include only interventions considered cost effective (with a cost <$Int6000 per DALY averted). These graphs reveal the cost implications of adding successively less cost effective or more comprehensive interventions, showing, for example, that the cumulative cost per capita associated with the provision of one of the more cost effective interventions for each of the three cancers is less than $Int1 in both regions.
Fig 1Incremental cost and cost effectiveness of interventions to combat breast, cervical, and colorectal cancer in WHO sub-Saharan African sub-region AfrE. See table 6 for explanation of intervention codes
Fig 2Incremental cost and cost effectiveness of interventions to combat breast, cervical, and colorectal cancer in WHO South East Asian sub-region SearD. See table 7 for explanation of intervention codes
The probabilistic uncertainty analysis depicted in figures 3 and 4 shows the impact of plausible variations in total costs and total effects and shows that the average cost effectiveness ratio of most interventions would retain their classification of highly cost effective or cost effective, after taking into account such uncertainty. A similar logic would apply to the incremental cost effectiveness ratios. One way sensitivity analysis (appendix 7 on bmj.com) shows that, for both sub-regions and all three diseases, removing age weights in the calculation of DALYs has a moderate impact on cost effectiveness (cost effectiveness ratio rising slightly or falling by up to 20%). Removing discounting as well as age weighting had a far larger influence, increasing health outcomes and thereby lowering (improving) cost effectiveness values markedly (by 45–90%).
Fig 3Probabilistic uncertainty analysis of interventions to breast, cervical and colorectal cancer in WHO sub-Saharan African sub-region Afr-E. See table 6 for explanation of intervention codes
Fig 4Probabilistic uncertainty analysis of interventions to breast, cervical and colorectal cancer in WHO South East Asian sub-region Sear-D. See table 7 for explanation of intervention codes
In addition, we performed a sensitivity analysis on the price of HPV vaccines: the approximate threshold price for HPV vaccine to become very cost effective is US$6 in sub-Saharan Africa and US$9 in South East Asia. If booster doses are required every 10 years, a cost as low as US$1.30 in sub-Saharan Africa and US$0.90 in South East Asia is required to render the intervention cost effective (data not shown).