A Simple Method to Estimate Tobacco-related Lung Cancer Deaths Based on Smoking Prevalence Data

Objective: Tobacco is the major cause of cancer and a relevant risk factor for several other chronic diseases. Due to the epidemiological transition in developing countries with overall increasing life expectancy there is an increasing relevance of chronic diseases to the total burden of diseases. Furthermore, there are indications for a rise in the consumption of tobacco products in developing countries. Since in Africa data on smoking prevalence are scarce and cancer diagnosis is often imprecise or missing, it is difficult to estimate the current and future number of cancer cases attributable to tobacco smoking. In this paper, we present an approach to estimate the effects of smoking on lung cancer in selected developing countries in Africa.

Methods: We combined data on smoking prevalence from different African countries with estimates on age-specific lung cancer rates in smokers and non-smokers from industrialized countries and data on age and sex distribution in African countries. We perform a sensitivity analysis to evaluate the effect of the assumptions necessary for the procedure.

Results: If the smoking prevalence in African countries will remain on the current level, we estimate age-specific lung cancer rates lower than those in Germany. Despite the relatively small proportion of adults aged 50 and more which is the age when most cancer cases occur, there is an appreciable number of deaths from lung cancer that could be prevented when smoking prevalence could be reduced. Depending on assumptions we estimate up about 50,000 lung cancer deaths per year in Africa, most of which could be prevented.

Conclusions: Efforts for smoking prevalence reduction are much more needed in the developing world. Better and more comprehensive data on smoking are needed for more precise estimates.

Willingness to pay for hypothetical malaria vaccines in rural Burkina Faso

Aims: This study aims to set priorities for anti-disease malaria vaccines by determining community preference in a hyperendemic area. Methods: A bidding game technique was used to elucidate willingness to pay in rural Burkina Faso and 2,326 adults were interviewed. Results: It is shown that there are significant differences between community preference for an anti-disease vaccine aimed at reducing pathology in pregnant women, and for a vaccine directed against childhood malaria. While the target population was willing to pay CFAfr 2101 for a vaccine against maternal malaria, its members were prepared to pay only CFAfr 1433 for a vaccine against childhood malaria. Conclusions: Whilst it is increasingly likely that anti-disease malaria vaccines will become available in the foreseeable future, lessons from the past suggest that a lack of acceptance and support from the intended recipients may lead to less than optimal compliance, and hence efficacy. For the planning of vaccine development and application strategies, it is therefore highly important to take community views into account. Here it is argued that such information could help researchers and funding agencies to set priorities for future vaccine research.

The Health and Demographic Surveillance System (HDSS) in Nouna, Burkina Faso, 1993-2007

The Nouna Health and Demographic Surveillance System (HDSS) is located in rural Burkina Faso and has existed since 1992. Currently, it has about 78,000 inhabitants. It is a member of the International Network for the Demographic Evaluation of Populations and Their Health in Developing Countries (INDEPTH), a global network of members who conducts longitudinal health and demographic evaluation of populations in low- and middle-income countries. The health facilities consist of one hospital and 13 basic health centres (locally known as CSPS). The Nouna HDSS has been used as a sampling frame for numerous studies in the fields of clinical research, epidemiology, health economics, and health systems research. In this paper we review some of the main findings, and we describe the effects that almost 20 years of health research activities have shown in the population in general and in terms of the perception, economic implications, and other indicators. Longitudinal data analyses show that childhood, as well as overall mortality, has significantly decreased over the observation period 1993–2007. The under-five mortality rate dropped from about 40 per 1,000 person-years in the mid-1990s to below 30 per 1,000 in 2007. Further efforts are needed to meet goal four of the Millennium Development Goals, which is to reduce the under-five mortality rate by two-thirds between 1990 and 2015.

Willingness to pay for maternal health outcomes: are women willing to pay more than men?

BACKGROUND

Only a limited number of studies have specifically sought to analyse and try to understand sex differences in willingness to pay (WTP).

OBJECTIVE

To identify the role of sex in determining monetary values placed upon improvements in maternal health in Burkina Faso, West Africa.

METHODS

A contingent valuation survey using the bidding game method was conducted in the district of Nouna in 2005; a sample of 409 male heads of households and their spouses were asked their WTP for a reduction in the number of maternal deaths in the Nouna area. Ordinary least squares regression analysis was employed to examine the determinants of WTP.

RESULTS

Men were willing to pay significantly more than women (3127 vs 2273 West African francs), although this represented a significantly smaller proportion of their annual income (4% vs 11%). In the multivariate analyses of all respondents there was a significant positive relationship between WTP values and both starting bid and whether there had been a previous maternal complication in the respondent's household. However, there was a significant negative relationship between WTP and female sex. Once interactions between sex and income were taken into account, income did affect valuations, with a positive relationship between higher-income women and WTP values.

CONCLUSION

In absolute terms, men were willing to pay more than women, while women were willing to pay a greater proportion of their income. Differences between men and women in their WTP, both in absolute terms and in terms of proportion of income, can be explained by a household effect. Future studies should distinguish between individual income and command over decision making with respect to use of individual and household income, and gain further insight into the strategies used by respondents in answering bidding game questions.

A game of two halves? Incentive incompatibility, starting point bias and the bidding game contingent valuation method

The bidding game (BG) method of contingent valuation is one way to increase the precision of willingness to pay (WTP) estimates relative to the single dichotomous choice approach. However, there is evidence that the method may lead to incentive incompatible responses and be associated with starting point bias. While previous studies in health using BGs test for starting point bias, none have also investigated incentive incompatibility. Using a sample of respondents resident in Burkina Faso, West Africa, this paper examines whether the BG method is associated with both incentive incompatibility and starting point bias. We find evidence for both effects. However, average WTP values remained largely unaffected after accounting for both factors in multivariate analyses. The results suggest that the BG method is an acceptable technique in settings where prices for goods are flexible.

Step-wedge cluster-randomised community-based trials: an application to the study of the impact of community health insurance

Background

We describe a step-wedge cluster-randomised community-based trial which has been conducted since 2003 to accompany the implementation of a community health insurance (CHI) scheme in West Africa. The trial aims at overcoming the paucity of evidence-based information on the impact of CHI. Impact is defined in terms of changes in health service utilisation and household protection against the cost of illness. Our exclusive focus on the description and discussion of the methods is justified by the fact that the study relies on a methodology previously applied in the field of disease control, but never in the field of health financing.

Methods

First, we clarify how clusters were defined both in respect of statistical considerations and of local geographical and socio-cultural concerns. Second, we illustrate how households within clusters were sampled. Third, we expound the data collection process and the survey instruments. Finally, we outline the statistical tools to be applied to estimate the impact of CHI.

Conclusion

We discuss all design choices both in relation to methodological considerations and to specific ethical and organisational concerns faced in the field. On the basis of the appraisal of our experience, we postulate that conducting relatively sophisticated trials (such as our step-wedge cluster-randomised community-based trial) aimed at generating sound public health evidence, is both feasible and valuable also in low income settings. Our work shows that if accurately designed in conjunction with local health authorities, such trials have the potential to generate sound scientific evidence and do not hinder, but at times even facilitate, the implementation of complex health interventions such as CHI.

The differences in characteristics between health-care users and non-users: implication for introducing community-based health insurance in Burkina Faso

The purposes of this study are to describe the characteristics of different health-care users, to explain such characteristics using a health demand model and to estimate the price-related probability change for different types of health care in order to provide policy guidance for the introduction of community-based health insurance (CBI) in Burkina Faso. Data were collected from a household survey using a two stage cluster sampling approach. Household interviews were carried out during April and May 2003. In the interviewed 7,939 individuals in 988 households, there were 558 people reported one or more illness episodes; two-thirds of these people did not seek professional care. Health care non-users display lower household income and expenditure, older age and lower perceived severity of disease. The main reason for choosing no-care and self-care was 'not enough money'. Multinomial logistic regression confirms these observations. Higher household cash-income, higher perceived severity of disease and acute disease significantly increased the probability of using western care. Older age and higher price-cash income ratio significantly increased the probability of no-care or self-care. If CBI were introduced the probability of using western care would increase by 4.33% and the probability of using self-care would reduce by 3.98%. The price-related probability change of using western care for lower income people is higher than for higher income although the quantity changed is relatively small. In conclusion, the introduction of CBI might increase the use of medical services, especially for the poor. Co-payment for the rich might be necessary. Premium adjusted for income or subsidies for the poor can be considered in order to absorb a greater number of poor households into CBI and further improve equity in terms of enrollment. However, the role of CBI in Burkina Faso is rather limited: it might only increase utilisation of western health care by a probability of 4%.

Revealing the burden of maternal mortality: a probabilistic model for determining pregnancy-related causes of death from verbal autopsies

Background

Substantial reductions in maternal mortality are called for in Millennium Development Goal 5 (MDG-5), thus assuming that maternal mortality is measurable. A key difficulty is attributing causes of death for the many women who die unaided in developing countries. Verbal autopsy (VA) can elicit circumstances of death, but data need to be interpreted reliably and consistently to serve as global indicators. Recent developments in probabilistic modelling of VA interpretation are adapted and assessed here for the specific circumstances of pregnancy-related death.

Methods

A preliminary version of the InterVA-M probabilistic VA interpretation model was developed and refined with adult female VA data from several sources, and then assessed against 258 additional VA interviews from Burkina Faso. Likely causes of death produced by the model were compared with causes previously determined by local physicians. Distinction was made between free-text and closed-question data in the VA interviews, to assess the added value of free-text material on the model's output.

Results

Following rationalisation between the model and physician interpretations, cause-specific mortality fractions were broadly similar. Case-by-case agreement between the model and any of the reviewing physicians reached approximately 60%, rising to approximately 80% when cases with a discrepancy were reviewed by an additional physician. Cardiovascular disease and malaria showed the largest differences between the methods, and the attribution of infections related to pregnancy also varied. The model estimated 30% of deaths to be pregnancy-related, of which half were due to direct causes. Data derived from free-text made no appreciable difference.

Conclusion

InterVA-M represents a potentially valuable new tool for measuring maternal mortality in an efficient, consistent and standardised way. Further development, refinement and validation are planned. It could become a routine tool in research and service settings where levels and changes in pregnancy-related deaths need to be measured, for example in assessing progress towards MDG-5.

Understanding enrolment in community health insurance in sub-Saharan Africa: a population-based case-control study in rural Burkina Faso

OBJECTIVE

To identify factors associated with decision to enrol in a community health insurance (CHI) scheme.

METHODS

We conducted a population-based case-control study among 15 communities offered insurance in 2004 in rural Burkina Faso. For inclusion in the study, we selected all 154 enrolled (cases) and a random sample of 393 non-enrolled (controls) households. We used unconditional logistic regression (applying Huber-White correction to account for clustering at the community level) to explore the association between enrolment status and a set of household head, household and community characteristics.

FINDINGS

Multivariate analysis revealed that enrolment in CHI was associated with Bwaba ethnicity, higher education, higher socioeconomic status, a negative perception of the adequacy of traditional care, a higher proportion of children living within the household, greater distance from the health facility, and a lower level of socioeconomic inequality within the community, but not with household health status or previous household health service utilization.

CONCLUSION

Our study provides evidence that the decision to enrol in CHI is shaped by a combination of household head, household, and community factors. Policies aimed at enhancing enrolment ought to act at all three levels. On the basis of our findings, we discuss specific policy recommendations and highlight areas for further research.

Determinants of household health expenditure on western institutional health care

We try to identify determinants of illness reporting, provider choice and resulting expenditure with different econometric models using data from a representative household panel survey of 800 households in Nouna health district, Burkina Faso, during 2000-2001. The factors "being an adult", "married", "illness occurred in rainy season" and "severe illness" significantly increased the magnitude of health expenditure. Compared to malaria, individuals spent more on other infectious diseases, injury and the other disease category. In contrast, people were less likely to spend on chronic illness. An individual who belonged to a household headed by a female, a literate household head and with a higher household expenditure had a significantly positive association with the magnitude of expenditure. Findings from this study can be used for policy implication to improve health system performance in Burkina Faso through enhancing health care utilization.

Cause-specific mortality rates in sub-Saharan Africa and Bangladesh

OBJECTIVE

To provide internationally comparable data on the frequencies of different causes of death.

METHODS

We analysed verbal autopsies obtained during 1999 -2002 from 12 demographic surveillance sites in sub-Saharan Africa and Bangladesh to find cause-specific and age-specific mortality rates. The cause-of-death codes used by the sites were harmonized to conform to the ICD-10 system, and summarized with the classification system of the Global Burden of Disease 2000 (Version 2).

FINDINGS

Causes of death in the African sites differ strongly from those in Bangladesh, where there is some evidence of a health transition from communicable to noncommunicable diseases, and little malaria. HIV dominates in causes of mortality in the South African sites, which contrast with those in highly malaria endemic sites elsewhere in sub-Saharan Africa (even in neighbouring Mozambique). The contributions of measles and diarrhoeal diseases to mortality in sub-Saharan Africa are lower than has been previously suggested, while malaria is of relatively greater importance.

CONCLUSION

The different patterns of mortality we identified may be a result of recent changes in the availability and effectiveness of health interventions against childhood cluster diseases.

A simple method to estimate tobacco-related lung cancer deaths based on smoking prevalence data

OBJECTIVE

Tobacco is the major cause of cancer and a relevant risk factor for several other chronic diseases. Due to the epidemiological transition in developing countries with overall increasing life expectancy there is an increasing relevance of chronic diseases to the total burden of diseases. Furthermore, there are indications for a rise in the consumption of tobacco products in developing countries. Since in Africa data on smoking prevalence are scarce and cancer diagnosis is often imprecise or missing, it is difficult to estimate the current and future number of cancer cases attributable to tobacco smoking. In this paper, we present an approach to estimate the effects of smoking on lung cancer in selected developing countries in Africa.

METHODS

We combined data on smoking prevalence from different African countries with estimates on age-specific lung cancer rates in smokers and non-smokers from industrialized countries and data on age and sex distribution in African countries. We perform a sensitivity analysis to evaluate the effect of the assumptions necessary for the procedure.

RESULTS

If the smoking prevalence in African countries will remain on the current level, we estimate age-specific lung cancer rates lower than those in Germany. Despite the relatively small proportion of adults aged 50 and more which is the age when most cancer cases occur, there is an appreciable number of deaths from lung cancer that could be prevented when smoking prevalence could be reduced. Depending on assumptions we estimate up about 50,000 lung cancer deaths per year in Africa, most of which could be prevented.

CONCLUSIONS

Efforts for smoking prevalence reduction are much more needed in the developing world. Better and more comprehensive data on smoking are needed for more precise estimates.

The feasibility of community-based health insurance in Burkina Faso

To ensure the acceptability of community-based insurance (CBI) by the community and its sustainability, a feasibility study of CBI was conducted in Burkina Faso, including preference for benefit package of CBI, costing of health services, costing of the benefit package and willingness-to-pay (WTP) for the package. Qualitative methods were used to collect information about preferences for the benefit package. Cost per unit health services, health demand obtained from household survey and physician-judged health needs were used to estimate the cost of the benefit package. The bidding game method was used to elicit household head's WTP for the package. We found that there were strong preferences for inclusion of high-cost healthservices such as operation, essential drugs and consultation fees in the benefit package. It is estimated that the cost of the package per capita was 1673 CFA (demand-based) and 9630 CFA (need-based), including 58% government subsidies (euro 1 = 655 CFA). The average household head with eight household members agreed to pay from 7500 (median) to 9769 CFA (mean) to join the CBI for his/her household. The WTP results were influenced by household characteristics, such as location, household size and age composition. Under certain assumptions (household as the enrolment unit, median household head's WTP as premium for the average household, 50% enrolment rate), it would be feasible to run CBI in Nouna, Burkina Faso if enrolees' health demand did not increase by more than 28% or if the underwriting of the initial losses was covered by extra funds.

Risk factors of infant and child mortality in rural Burkina Faso

OBJECTIVE

The aim of the study was to quantify the effect of risk factors for childhood mortality in a typical rural setting in sub-Saharan Africa.

METHODS

We performed a survival analysis of births within a population under demographic surveillance from 1992 to 1999 based on data from a demographic surveillance system in 39 villages around Nouna, western Burkina Faso, with a total population of about 30000. All children born alive in the period 1 January 1993 to 31 December 1999 in the study area (n = 10 122) followed-up until 31 December 1999 were included. All-cause childhood mortality was used as outcome variable.

FINDINGS

Within the observation time, 1340 deaths were recorded. In a Cox regression model a simultaneous estimation of hazard rate ratios showed death of the mother and being a twin as the strongest risk factors for mortality. For both, the risk was most pronounced in infancy. Further factors associated with mortality include age of the mother, birth spacing, season of birth, village, ethnic group, and distance to the nearest health centre. Finally, there was an overall decrease in childhood mortality over the years 1993-99.

CONCLUSION

The study supports the multi-causation of childhood deaths in rural West Africa during the 1990s and supports the overall trend, as observed in other studies, of decreasing childhood mortality in these populations. The observed correlation between the factors highlights the need for multivariate analysis to disentangle the separate effects. These findings illustrate the need for more comprehensive improvement of prenatal and postnatal care in rural sub-Saharan Africa.

Mortality patterns, 1993-98, in a rural area of Burkina Faso, West Africa, based on the Nouna demographic surveillance system

The Nouna demographic surveillance system database was analysed for the period 1993-98. Basic demographic parameters, age-specific and age-standardized mortality rates were calculated and a seasonal variation in mortality was analysed. Poisson regression was used to model the calculated mortality rates and to investigate the seasonal mortality pattern. Both the population distribution by age and the mortality rates reflect a typical pattern of population structures and total mortality in rural Africa as a whole: high childhood mortality and a young population (about 60% are up to age 25; about 10% above age 64). We identified a significant seasonal pattern with highest mortality rates in February. Demographic surveillance systems in Africa provide a viable method for the collection of reliable data on vital events in rural Africa and should therefore be established and supported.

Examining out-of-pocket expenditure on health care in Nouna, Burkina Faso: implications for health policy

OBJECTIVE

To examine household out-of-pocket expenditure on health care, particularly malaria treatment, in rural Burkina Faso.

METHOD

Comprehensive analysis of out-of-pocket expenditure on health care through a descriptive analysis and a second, multivariate analysis using the Tobit model with emphasis on malaria, based on 800 urban and rural households in Nouna health district.

RESULTS

Households will spend less on malaria, either in or outside the health facility, if given the choice to do so, because they feel confident to self-treat malaria. Seeking health care from a qualified health worker incurs more out-of-pocket expenditure than self-treatment and traditional healers, and if necessary, households sell off assets to offset the expenditure. More than 80% of household out-of-pocket expenditure is allocated to drugs.

CONCLUSION

This has policy implications for malaria control and the Roll Back Malaria Initiative. Communities need to be educated on the risks of malaria complications and the potential risk of inappropriate diagnosis and treatment. Drug or health services pricing policy needs to create an incentive to use the health services. In the fight against malaria, building alliances between households, traditional healers and health workers is essential.

Effect of zinc supplementation on malaria and other causes of morbidity in west African children: randomised double blind placebo controlled trial

OBJECTIVE

To study the effects of zinc supplementation on malaria and other causes of morbidity in young children living in an area holoendemic for malaria in west Africa.

DESIGN

Randomised, double blind, placebo controlled efficacy trial.

SETTING

18 villages in rural northwestern Burkina Faso.

PARTICIPANTS

709 children were enrolled; 685 completed the trial.

INTERVENTION

Supplementation with zinc (12.5 mg zinc sulphate) or placebo daily for six days a week for six months.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of symptomatic falciparum malaria. Secondary outcomes were the severity of malaria episodes, prevalence of malaria parasite, mean parasite densities, mean packed cell volume, prevalence of other morbidity, and all cause mortality.

RESULTS

The mean number of malaria episodes per child (defined as a temperature >/=37.5 degrees C with >/=5000 parasites/microliter) was 1.7, 99.7% due to infection with Plasmodium falciparum. No difference was found between the zinc and placebo groups in the incidence of falciparum malaria (relative risk 0.98, 95% confidence interval 0.86 to 1.11), mean temperature, and mean parasite densities during malaria episodes, nor in malaria parasite rates, mean parasite densities, and mean packed cell volume during cross sectional surveys. Zinc supplementation was significantly associated with a reduced prevalence of diarrhoea (0.87, 0.79 to 0.95). All cause mortality was non-significantly lower in children given zinc compared with those given placebo (5 v 12, P=0.1).

CONCLUSIONS

Zinc supplementation has no effect on morbidity from falciparum malaria in children in rural west Africa, but it does reduce morbidity associated with diarrhoea.

Measuring the local burden of disease. A study of years of life lost in sub-Saharan Africa

BACKGROUND

An effective health policy necessitates a reliable characterization of the burden of disease (BOD) by cause. The Global Burden of Disease Study (GBDS) aims to deliver this information. For sub-Saharan Africa (SSA) in particular, the GBDS relies on extrapolations and expert guesses. Its results lack validation by locally measured epidemiological data.

METHODS

This study presents locally measured BOD data for a health district in Burkina Faso and compares them to the results of the GBDS for SSA. As BOD indicator, standard years of life lost (age-weighted YLL, discounted with a discount rate of 3%) are used as proposed by the GBDS. To investigate the influence of different age and time preference weights on our results, the BOD pattern is again estimated using, first, YLL with no discounting and no age-weighting, and, second, mortality figures.

RESULTS

Our data exhibit the same qualitative BOD pattern as the GBDS results regarding age and gender. We estimated that 53.9% of the BOD is carried by men, whereas the GBDS reported this share to be 53.2%. The ranking of diseases by BOD share, though, differs substantially. Malaria, diarrhoeal diseases and lower respiratory infections occupy the first three ranks in our study and in the GBDS, only differing in their respective order. Protein-energy malnutrition, bacterial meningitis and intestinal nematode infections occupy ranks 5, 6 and 7 in Nouna but ranks 15, 27 and 38 in the GBDS. The results are not sensitive to the different age and time preference weights used. Specifically, the choice of parameters matters less than the choice of indicator.

CONCLUSIONS

Local health policy should rather be based on local BOD measurement instead of relying on extrapolations that might not represent the true BOD structure by cause.