BACKGROUND: Quality-adjusted life-years (QALYs) have been used since the 1980s as a standard health outcome measure for conducting cost-utility analyses, which are often inadequately labeled as 'cost-effectiveness analyses'. This synthetic outcome, which combines the quantity of life lived with its quality expressed as a preference score, is currently recommended as reference case by some health technology assessment (HTA) agencies. While critics of the QALY approach have expressed concerns about equity and ethical issues, surprisingly, very few have tested the basic methodological assumptions supporting the QALY equation so as to establish its scientific validity. OBJECTIVES: the main objective of the ECHOUTCOME European project was to test the validity of the underlying assumptions of the QALY outcome and its relevance in health decision making. METHODS: an experiment has been conducted with 1,361 subjects from Belgium, France, Italy, and the UK. The subjects were asked to express their preferences regarding various hypothetical health states derived from combining different health states with time durations in order to compare observed utility values of the couples (health state, time) and calculated utility values using the QALY formula. RESULTS: Observed and calculated utility values of the couples (health state, time) were significantly different, confirming that preferences expressed by the respondents were not consistent with the QALY theoretical assumptions. CONCLUSIONS: This European study contributes to establishing that the QALY multiplicative model is an invalid measure. This explains why costs/QALY estimates may vary greatly, leading to inconsistent recommendations relevant to providing access to innovative medicines and health technologies. HTA agencies should consider other more robust methodological approaches to guide reimbursement decisions.

BACKGROUND: the evidence on determinants of individuals' choices for anti-malarial drug treatments is scarce. This study sought to measure the strength of preference for adult antimalarial drug treatment attributes of heads of urban, rural and peri-urban households in a resource-limited malaria-endemic area of sub-Saharan Africa. METHODS: Discrete choice experiments were conducted with 508 heads of household interviewed face-to-face for a household population survey of health-seeking behavior in Zomba District, Malawi. The interviews were held in Chichewa and the choice experiment questions were presented with cartoon aids. The anti-malarial drug attributes included in the stated preference experiment were: speed of fever resolution, side effects (pruritus) risk, protection (duration of prophylactic effect), price, duration of treatment course and recommendation by a health professional. Sixteen treatment profiles from a fractional factorial design by orthogonal array were paired into choice scenarios, and scenarios were randomly assigned to participants so that each participant was presented with a series of eight pairwise choice scenarios. Respondents had the option to state indifference between the two profiles or decline to choose. Data were analysed in a mixed logit model, with normally distributed coefficients for all six attributes. RESULTS: the sex ratio was balanced in urban areas, whereas 63% of participants in rural areas were male. The proportion of individuals with no education was considerably higher in the rural group (25%) than in the urban (5%) and peri-urban (6%) groups. All attributes investigated had the expected influence, and traded-off in most respondents' choices. There were heterogeneous effects of price, pruritus risk, treatment recommendation by a professional, and duration of prophylaxis across respondents, only partly explained by their differences in education, household per capita expenditure, sex and age. Individuals' demand elasticity (simulated median, inter-quartile range) was highest (most responsive) to speed of symptom resolution (0.88, 0.80-0.89) and pruritus risk (0.25, 0.08-0.62). CONCLUSIONS: Most adult antimalarial users are willing to use treatments without recommendation from health professional, and may be influenced by price. Future studies should investigate the magnitude of differences in price and treatment attribute sensitivity between adult anti-malarial drug users in rural, peri-urban and urban areas in order to determine optimal price subsidies.

OBJECTIVE: Several countries in sub-Saharan Africa have implemented policies to remove or reduce user fees. Our aim was to identify criteria guiding such decisions among national policy entrepreneurs, those who link up problem definition, solution development and political processes. METHODS: We administered a best-worst scaling (BWS) experiment to 89 policy entrepreneurs, asking them to identify the most and the least important criteria on a series of predefined sets. Sets were compiled using a Balance Incomplete Block Design which generated random combinations of all 11 criteria included in the experiment. In turn, those had emerged from a prior set of focus group discussions organized among policy entrepreneurs. Ordered logit models were used to investigate the value of single criteria as well as heterogeneity of preferences. RESULTS: Political commitment was identified as the most important criterion guiding policy decisions on user fee abolition or reduction to the overall sample, but particularly so for more experienced respondents aged over 50 years. International pressure and donor money were identified as least important while equity and institutional capacity were deemed of relatively little importance. Respondents more involved in advising on policy than on formulating policy rated economic issues such as financial sustainability and cost-effectiveness as less important. CONCLUSIONS: it is feasible to apply BWS experiments in low-income countries, although whether the technique can be adjusted to elicit preferences among non-literate respondents in these settings is unclear.

BACKGROUND: over 133,000 children present to hospitals with Acute Encephalitis Syndrome (AES) annually in Asia. Japanese encephalitis (JE) accounts for approximately one-quarter of cases; in most cases no pathogen is identified and management is supportive. Although JE is known to result in neurological impairment, few studies have examined the wider impact of JE and AES on patients and their families. METHODOLOGY/PRINCIPAL FINDINGS: Children (aged 1 month-14 years) with AES were assessed 5-12 months after discharge from two Nepali hospitals. Assessment included clinical examination, the Liverpool Outcome Score (LOS) - a validated assessment of function following encephalitis, questionnaires about the child's social participation since discharge, and out-of-pocket costs to the family. Children were classified as JE or 'other AES' based on anti-JE virus antibody titres during acute illness. Contact was made with the families of 76% (73/96) of AES children. Six children had died and one declined participation. 48% (32/66) reported functional impairment at follow-up, most frequently affecting behaviour, language or limb use. Impairment was more frequent in JE compared to 'other AES' cases (68% [13/19] versus 40% [19/47]; p = 0.06). 49% (26/53) had improvement in LOS between discharge and follow-up. The median out-of-pocket cost to families, including medical bills, medication and lost earnings was US$ 1151 (10 times their median monthly income) for children with severe/moderate impairment and $524 (4.6 times their income) for those with mild/no impairment (P = 0.007). Acute admission accounted for 74% of costs. Social participation was limited in 21% of children (n = 14). CONCLUSIONS/SIGNIFICANCE: Prolonged functional impairment was common following AES. Economic impact to families was substantial. Encouragingly, almost half the children improved after discharge and most reported sustained social participation. This study highlights a need for long-term medical support following AES. Rationalisation of initial expensive hospital treatments may be warranted, especially since only supportive treatment is available.

Antiretroviral therapy (ART) improves the quality of life of people living with HIV/AIDS. However, adherence remains a challenge. A total of eight focus group discussions (FGD) were conducted with participants from a randomised controlled trial that monitored strategies for managing ART in African adults: Development of Antiretroviral Therapy. All FGD participants had received ART for at least one year. Perceived benefits of ART were key motivators for adherence. These benefits included improved physical health, restored self-esteem, acceptance in the community and hope for a longer and healthier life and reduced fear of HIV/AIDS-related death. Barriers to adherence included a high pill burden, ART side effects and socio-economic constraints, including lack of food and safe water for taking the pills. Visible ART side effects and involvement in an exclusively HIV/AIDS clinic could expose their HIV status, thus exacerbating stigma. Gender and socio-economic differences were found in the variety of strategies employed to ensure adherence. ART was perceived as improving the overall quality of life of recipients; however, it is crucial for ART programmes to be gender and socio-economic cognizant in order to enhance adherence to a lifelong therapy.

Background: Anaemia is a common side-effect of cancer treatments and can lead to a reduction in quality of life. Erythropoiesis-stimulating agents (ESAs) are licensed for use in conjunction with red blood cell transfusions (RBCTs) to improve cancer treatment-induced anaemia (CIA).
Methods: the clinical effectiveness review followed principles published by NHS CRD. Randomised controlled trials (RCTs), or systematic reviews of RCTs, of ESAs (epoetin or darbepoetin) for treating people with CIA were eligible for inclusion in the review. Comparators were best supportive care (BSC), placebo, or other ESA. Anaemia- and malignancy-related outcomes, health-related quality of life (HRQoL), and adverse events (AEs) were evaluated. Where appropriate, data were pooled using meta-analysis. An empirical health economic model was developed comparing ESA treatment to no ESA treatment. The model has two components: one evaluating short-term costs and QALYs (while patients are anaemic); and one evaluating long-term QALYs. Costs and benefits were discounted at 3.5% pa. Probabilistic and univariate deterministic sensitivity analyses were performed.
Results: Twenty-three studies assessing ESAs within their licensed indication (based on start dose administered) were included. None of the RCTs were completely aligned with current EU licenses. Results suggest that there is clinical benefit from ESAs for anaemia-related outcomes. Data suggest improvement in HRQoL scores. The impact of ESAs on AEs and survival remains highly uncertain; although point estimates are lower confidence intervals are wide and not statistically significant. Base case incremental cost-effectiveness ratios (ICERs) for ESA treatment versus no ESA treatment ranged from £19,429–£35,018 per quality-adjusted life year (QALY) gained, but sensitivity and scenario analyses demonstrate considerable uncertainty in these ICERs, including the possibility of overall health disbenefit. All ICERs were sensitive to survival and cost.
Conclusions: ESAs could be cost-effective when used closer to licence but there is considerable uncertainty mainly due to unknown impacts on overall survival.

OBJECTIVE: Investigators within many disciplines are using measures of well-being, but it is not always clear what they are measuring, or which instruments may best meet their objectives. The aims of this review were to: systematically identify well-being instruments, explore the variety of well-being dimensions within instruments and describe how the production of instruments has developed over time. DESIGN: Systematic searches, thematic analysis and narrative synthesis were undertaken. DATA SOURCES: MEDLINE, EMBASE, EconLit, PsycINFO, Cochrane Library and CINAHL from 1993 to 2014 complemented by web searches and expert consultations through 2015. ELIGIBILITY CRITERIA: Instruments were selected for review if they were designed for adults (≥18â€
years old), generic (ie, non-disease or context specific) and available in an English version. RESULTS: a total of 99 measures of well-being were included, and 196 dimensions of well-being were identified within them. Dimensions clustered around 6 key thematic domains: mental well-being, social well-being, physical well-being, spiritual well-being, activities and functioning, and personal circumstances. Authors were rarely explicit about how existing theories had influenced the design of their tools; however, the 2 most referenced theories were Diener's model of subjective well-being and the WHO definition of health. The period between 1990 and 1999 produced the greatest number of newly developed well-being instruments (n=27). An illustration of the dimensions identified and the instruments that measure them is provided within a thematic framework of well-being. CONCLUSIONS: This review provides researchers with an organised toolkit of instruments, dimensions and an accompanying glossary. The striking variability between instruments supports the need to pay close attention to what is being assessed under the umbrella of 'well-being' measurement.

© 2016. Introduction: Chemotherapy-induced diarrhea (CID) diminishes physical performance, raises anxiety and depression levels, and increases healthcare resource utilization. Objective: to understand the impact that CID has on health-related quality of life (HRQoL) and on healthcare resource utilization. Methods: Systematic searches were conducted in MEDLINE, EMBASE, DARE, and the NHS EED databases. Results: a total of 22 articles were retrieved for full review (n = 17, HRQoL; n = 5 healthcare resource utilization). Only 2 studies had assessed HRQoL in patients experiencing CID, while cost studies demonstrated that CID episodes are unnecessarily expensive and can be avoided if diagnosed and treated early. Conclusions: Better management of CID has the potential to reduce overall economic burden and improve patients' HRQoL. Available evidence also relays the need to conduct larger studies that assess HRQoL and consider cost beyond direct medical costs in order to understand the full impact of CID on HRQoL and healthcare resource utilization.

BACKGROUND: Viral encephalitis is a devastating condition for which delayed treatment is associated with increased morbidity and mortality. Clinical audits indicate substantial scope for improved detection and treatment. Improvement strategies should ideally be tailored according to identified needs and barriers to change. The aim of the study is to evaluate the effectiveness and cost-effectiveness of a tailored intervention to improve the secondary care management of suspected encephalitis. METHODS/DESIGN: the study is a two-arm cluster randomised controlled trial with allocation by postgraduate deanery. Participants were identified from 24 hospitals nested within 12 postgraduate deaneries in the United Kingdom (UK). We developed a multifaceted intervention package including core and flexible components with embedded behaviour change techniques selected on the basis of identified needs and barriers to change. The primary outcome will be a composite of the proportion of patients with suspected encephalitis receiving timely and appropriate diagnostic lumbar puncture within 12 h of hospital admission and aciclovir treatment within 6 h. We will gather outcome data pre-intervention and up to 12 months post-intervention from patient records. Statistical analysis at the cluster level will be blind to allocation. An economic evaluation will estimate intervention cost-effectiveness from the health service perspective. TRIAL REGISTRATION: Controlled Trials: ISRCTN06886935.

BACKGROUND: Quality-adjusted life-years (QALYs) have been used since the 1980s as a standard health outcome measure for conducting cost-utility analyses, which are often inadequately labeled as 'cost-effectiveness analyses'. This synthetic outcome, which combines the quantity of life lived with its quality expressed as a preference score, is currently recommended as reference case by some health technology assessment (HTA) agencies. While critics of the QALY approach have expressed concerns about equity and ethical issues, surprisingly, very few have tested the basic methodological assumptions supporting the QALY equation so as to establish its scientific validity. OBJECTIVES: the main objective of the ECHOUTCOME European project was to test the validity of the underlying assumptions of the QALY outcome and its relevance in health decision making. METHODS: an experiment has been conducted with 1,361 subjects from Belgium, France, Italy, and the UK. The subjects were asked to express their preferences regarding various hypothetical health states derived from combining different health states with time durations in order to compare observed utility values of the couples (health state, time) and calculated utility values using the QALY formula. RESULTS: Observed and calculated utility values of the couples (health state, time) were significantly different, confirming that preferences expressed by the respondents were not consistent with the QALY theoretical assumptions. CONCLUSIONS: This European study contributes to establishing that the QALY multiplicative model is an invalid measure. This explains why costs/QALY estimates may vary greatly, leading to inconsistent recommendations relevant to providing access to innovative medicines and health technologies. HTA agencies should consider other more robust methodological approaches to guide reimbursement decisions.

© the Author 2013. In a randomized comparison of nevirapine or abacavir with zidovudine plus lamivudine, routine viral load monitoring was not performed, yet 27% of individuals with viral failure at week 48 experienced resuppression by week 96 without switching. This supports World Health Organization recommendations that suspected viral failure should trigger adherence counseling and repeat measurement before a treatment switch is considered.

© 2016. Introduction: Cancer anorexia-cachexia syndrome (CACS) negatively impacts patients' quality of life (QoL) and increases the burden on healthcare resources. Objectives: to review published CACS data regarding health-related QOL (HRQoL) and its economic impact on the healthcare system. Methods: Searches were conducted in MEDLINE, EMBASE, DARE, and NHS EED databases. Results: a total of 458 HRQoL and 189 healthcare resources utilisation abstracts were screened, and 42 and 2 full-text articles were included, respectively.The EORTC QLQ-C30 and FAACT instruments were most favoured for assessing HRQOL but none of the current tools cover all domains affected by CACS. Economic estimates for managing CACS are scarce, with studies lacking a breakdown of healthcare resource utilisation items. Conclusions: HRQoL instruments that can better assess and incorporate all the domains affected by CACS are required. Rigorous assessment of costs and benefits of treatment are needed to understand the magnitude of the impact of CACS.

BACKGROUND: the evidence on determinants of individuals' choices for anti-malarial drug treatments is scarce. This study sought to measure the strength of preference for adult antimalarial drug treatment attributes of heads of urban, rural and peri-urban households in a resource-limited malaria-endemic area of sub-Saharan Africa. METHODS: Discrete choice experiments were conducted with 508 heads of household interviewed face-to-face for a household population survey of health-seeking behavior in Zomba District, Malawi. The interviews were held in Chichewa and the choice experiment questions were presented with cartoon aids. The anti-malarial drug attributes included in the stated preference experiment were: speed of fever resolution, side effects (pruritus) risk, protection (duration of prophylactic effect), price, duration of treatment course and recommendation by a health professional. Sixteen treatment profiles from a fractional factorial design by orthogonal array were paired into choice scenarios, and scenarios were randomly assigned to participants so that each participant was presented with a series of eight pairwise choice scenarios. Respondents had the option to state indifference between the two profiles or decline to choose. Data were analysed in a mixed logit model, with normally distributed coefficients for all six attributes. RESULTS: the sex ratio was balanced in urban areas, whereas 63% of participants in rural areas were male. The proportion of individuals with no education was considerably higher in the rural group (25%) than in the urban (5%) and peri-urban (6%) groups. All attributes investigated had the expected influence, and traded-off in most respondents' choices. There were heterogeneous effects of price, pruritus risk, treatment recommendation by a professional, and duration of prophylaxis across respondents, only partly explained by their differences in education, household per capita expenditure, sex and age. Individuals' demand elasticity (simulated median, inter-quartile range) was highest (most responsive) to speed of symptom resolution (0.88, 0.80-0.89) and pruritus risk (0.25, 0.08-0.62). CONCLUSIONS: Most adult antimalarial users are willing to use treatments without recommendation from health professional, and may be influenced by price. Future studies should investigate the magnitude of differences in price and treatment attribute sensitivity between adult anti-malarial drug users in rural, peri-urban and urban areas in order to determine optimal price subsidies.

OBJECTIVE: Several countries in sub-Saharan Africa have implemented policies to remove or reduce user fees. Our aim was to identify criteria guiding such decisions among national policy entrepreneurs, those who link up problem definition, solution development and political processes. METHODS: We administered a best-worst scaling (BWS) experiment to 89 policy entrepreneurs, asking them to identify the most and the least important criteria on a series of predefined sets. Sets were compiled using a Balance Incomplete Block Design which generated random combinations of all 11 criteria included in the experiment. In turn, those had emerged from a prior set of focus group discussions organized among policy entrepreneurs. Ordered logit models were used to investigate the value of single criteria as well as heterogeneity of preferences. RESULTS: Political commitment was identified as the most important criterion guiding policy decisions on user fee abolition or reduction to the overall sample, but particularly so for more experienced respondents aged over 50 years. International pressure and donor money were identified as least important while equity and institutional capacity were deemed of relatively little importance. Respondents more involved in advising on policy than on formulating policy rated economic issues such as financial sustainability and cost-effectiveness as less important. CONCLUSIONS: it is feasible to apply BWS experiments in low-income countries, although whether the technique can be adjusted to elicit preferences among non-literate respondents in these settings is unclear.

BACKGROUND: over 133,000 children present to hospitals with Acute Encephalitis Syndrome (AES) annually in Asia. Japanese encephalitis (JE) accounts for approximately one-quarter of cases; in most cases no pathogen is identified and management is supportive. Although JE is known to result in neurological impairment, few studies have examined the wider impact of JE and AES on patients and their families. METHODOLOGY/PRINCIPAL FINDINGS: Children (aged 1 month-14 years) with AES were assessed 5-12 months after discharge from two Nepali hospitals. Assessment included clinical examination, the Liverpool Outcome Score (LOS) - a validated assessment of function following encephalitis, questionnaires about the child's social participation since discharge, and out-of-pocket costs to the family. Children were classified as JE or 'other AES' based on anti-JE virus antibody titres during acute illness. Contact was made with the families of 76% (73/96) of AES children. Six children had died and one declined participation. 48% (32/66) reported functional impairment at follow-up, most frequently affecting behaviour, language or limb use. Impairment was more frequent in JE compared to 'other AES' cases (68% [13/19] versus 40% [19/47]; p = 0.06). 49% (26/53) had improvement in LOS between discharge and follow-up. The median out-of-pocket cost to families, including medical bills, medication and lost earnings was US$ 1151 (10 times their median monthly income) for children with severe/moderate impairment and $524 (4.6 times their income) for those with mild/no impairment (P = 0.007). Acute admission accounted for 74% of costs. Social participation was limited in 21% of children (n = 14). CONCLUSIONS/SIGNIFICANCE: Prolonged functional impairment was common following AES. Economic impact to families was substantial. Encouragingly, almost half the children improved after discharge and most reported sustained social participation. This study highlights a need for long-term medical support following AES. Rationalisation of initial expensive hospital treatments may be warranted, especially since only supportive treatment is available.

Antiretroviral therapy (ART) improves the quality of life of people living with HIV/AIDS. However, adherence remains a challenge. A total of eight focus group discussions (FGD) were conducted with participants from a randomised controlled trial that monitored strategies for managing ART in African adults: Development of Antiretroviral Therapy. All FGD participants had received ART for at least one year. Perceived benefits of ART were key motivators for adherence. These benefits included improved physical health, restored self-esteem, acceptance in the community and hope for a longer and healthier life and reduced fear of HIV/AIDS-related death. Barriers to adherence included a high pill burden, ART side effects and socio-economic constraints, including lack of food and safe water for taking the pills. Visible ART side effects and involvement in an exclusively HIV/AIDS clinic could expose their HIV status, thus exacerbating stigma. Gender and socio-economic differences were found in the variety of strategies employed to ensure adherence. ART was perceived as improving the overall quality of life of recipients; however, it is crucial for ART programmes to be gender and socio-economic cognizant in order to enhance adherence to a lifelong therapy.

As antiretroviral treatment (ART) for HIV/AIDS is scaled up globally, information on per-person costs is critical to improve efficiency in service delivery and to maximize coverage and health impact. The objective of this study was to review studies on unit costs for delivery of adult and paediatric ART per patient-year, and prevention of mother-to-child transmission (PMTCT) interventions per mother-infant pair screened or treated, in low- and middle-income countries. A systematic review was conducted of English, French and Spanish publications from 2001 to 2009, reporting empirical costing that accounted for at least antiretroviral (ARV) medicines, laboratory testing and personnel. Expenditures were analysed by country-income level and cost component. All costs were standardized to $US, year 2009 values. Several sensitivity analyses were conducted. Analyses covered 29 eligible, comprehensive, costing studies. In the base case, in low-income countries (LIC), median ART cost per patient-year was $US792 (mean: 839, range: 682-1089); for lower-middle-income countries (LMIC), the median was $US932 (mean: 1246, range: 156-3904); and, for upper-middle-income countries (UMIC), the median was $US1454 (mean: 2783, range: 1230-5667). ARV drugs were the largest component of overall ART costs in all settings (64%, 50% and 47% in LIC, LMIC and UMIC, respectively). of 26 ART studies, 14 reported the drug regimes used, and only one study explicitly reported second-line treatment costs. The second cost driver was laboratory cost in LIC and LMIC (14% and 20%), and personnel costs in UMIC (26%). Two ART studies specified the types of laboratory tests costed, and three studies specifically included above facility-level personnel costs. Three studies reported detailed PMTCT costs, and three studies reported on paediatric ART. There is a paucity of data on the full unit costs for delivery of ART and PMTCT, particularly for LIC and middle-income countries. Heterogeneity in activities costed, and insufficient detail regarding components included in the costing, hampers standardization of unit cost measures. Evaluation of programme-level unit costs would benefit from international guidance on standardized costing methods, and expenditure categories and definitions. Future work should help elucidate the sources of the large variations in delivery unit costs across settings with similar income and epidemiological characteristics.

In 1975, the World Health Assembly recommended that blood for transfusion should come from voluntary, non-remunerated donors; yet, in Africa, 75-80% of blood for transfusion still comes from hospital-based replacement donors. Although comprehensive economic data are scarce, evidence indicates that blood from voluntary donors recruited and screened at centralized transfusion centres, costs four to eight times as much as blood from a hospital-based, replacement donor system. Donor recruitment, quality assurance systems and distribution mechanisms in the centralized system are major reasons for the cost difference. There are concerns about the sustainability of centralized voluntary donor systems and their compatibility with the levels of health care that exist in many poor countries yet burdening patients' families with the responsibility of finding replacement blood donors will exacerbate poverty and reduce the safety of the blood supply. There are measures that can be introduced into hospital-based systems to improve safe blood supply in Africa but their effectiveness in different contexts needs to be evaluated.

AIMS: to evaluate the characteristics of manual haemoglobin methods in use in Malawi and provide evidence for the Ministry of Health in Malawi to enable them to choose a suitable method for district hospitals. METHODS: Criteria on accuracy, clinical usefulness, user friendliness, speed, training time, and economic costs were determined by local health professionals and used to compare six different manual haemoglobin methods. These were introduced sequentially into use in a district hospital in Malawi alongside the reference method. RESULTS: HemoCue was the optimal method based on most of the outcome measures but was also the most expensive (0.75 US dollars/test). DHT meter and Jenway colorimeter were the second choice because they were cheaper (0.20-0.35 US dollars/test), but they were not as accurate or user friendly as HemoCue. CONCLUSIONS: the process for choosing appropriate laboratory methods is complex and very little guidance is available for health managers in poorer countries. This paper describes the development and testing of a practical model for gathering evidence about test efficiency that could be adapted for use in other resource poor settings.

A high burden of malaria, tuberculosis, and HIV infection contributes to national and individual poverty. We have reviewed a broad range of evidence detailing factors at individual, household, and community levels that influence vulnerability to malaria, tuberculosis, and HIV infection and used this evidence to identify strategies that could improve resilience to these diseases. This first part of the review explores the concept of vulnerability to infectious diseases and examines how age, sex, and genetics can influence the biological response to malaria, tuberculosis, and HIV infection. We highlight factors that influence processes such as poverty, livelihoods, gender discrepancies, and knowledge acquisition and provide examples of how approaches to altering these processes may have a simultaneous effect on all three diseases.

A study of unit costs and cost components of two malaria-control strategies (house spraying and bednet impregnation with residual insecticides) was undertaken in 11 malaria-endemic states (departamentos) of Colombia, using data provided by control staff on self-administered questionnaires. The accuracy of the data was verified by personal visits, telephone conversations and complementary information from 10 other states. Allthe financial-cost components of the malaria-control operations carried out in the previous 6 months and the results of the control operations themselves (including the numbers of houses sprayed and numbers of bednets impregnated/day) were recorded. The information was stratified according to whether the target communities were 'near' or 'far away' from an operational base, the far-away communities being those that needed overnight stays by the control staff. The main variables analysed were unit costs/house treated, and annual cost/person protected. The results show that house spraying was generally more expensive for the health services than bednet impregnation. This is particularly the case in 'nearby' communities, where most of those at-risk live. In such communities, spraying one house was 7.2 times more expensive than impregnating one bednet. Even if only those sleeping under an impregnated net were assumed to be protected, the unit costs/person protected in a 'nearby' community were twice as high for house spraying than for bednet impregnation. In 'nearby' communities, where technicians could return to the operational base each evening, insecticides made up 80% of the total spraying costs and 42% of the costs of bednet impregnation. In 'far-away' communities, however, salaries and 'per diems' were the most important cost components, representing, respectively, 23% and 22% of the costs of spraying, and 34% plus 27% of the costs of impregnation. Insecticide wastage and non-use of discounts on insecticide prices (available through the national Ministry of Health) increased the overall costs considerably. The multiple uses of these cost calculations for district health managers are presented.