Loss to 5-year follow-up in the population-based Telemark Study: risk factors and potential for bias

OBJECTIVES

This study aimed to characterise participants lost to follow-up and identify possible factors associated with non-participation in a prospective population-based study of respiratory health in Norway. We also aimed to analyse the impact of potentially biased risk estimates associated with a high proportion of non-responders.

DESIGN

Prospective 5-year follow-up study.

SETTING

Randomly selected inhabitants from the general population of Telemark County in south-eastern Norway were invited to fill in a postal questionnaire in 2013. Responders in 2013 were followed-up in 2018.

PARTICIPANTS

16 099 participants aged 16-50 years completed the baseline study. 7958 responded at the 5-year follow-up, while 7723 did not.

MAIN OUTCOME MEASURES

χ² test was performed to compare demographic and respiratory health-related characteristics between those who participated in 2018 and those who were lost to follow-up. Adjusted multivariable logistic regression models were used to assess the relationship between loss to follow-up, background variables, respiratory symptoms, occupational exposure and interactions, and to analyse whether loss to follow-up leads to biased risk estimates.

RESULTS

7723 (49%) participants were lost to follow-up. Loss to follow-up was significantly higher for male participants, those in the youngest age group (16-30 years), those in lowest education level category and among current smokers (all p<0.001). In multivariable logistic regression analysis, loss to follow-up was significantly associated with unemployment (OR 1.34, 95% CI 1.22 to 1.46), reduced work ability (1.48, 1.35 to 1.60), asthma (1.22, 1.10 to 1.35), being woken by chest tightness (1.22, 1.11 to 1.34) and chronic obstructive pulmonary disease (1.81, 1.30 to 2.52). Participants with more respiratory symptoms and exposure to vapour, gas, dust and fumes (VGDF) (1.07 to 1.00-1.15), low-molecular weight (LMW) agents (1.19, 1.00 to 1.41) and irritating agents (1.15, 1.05 to 1.26) were more likely to be lost to follow-up. We found no statistically significant association of wheezing and exposure to LMW agents for all participants at baseline (1.11, 0.90 to 1.36), responders in 2018 (1.12, 0.83 to 1.53) and those lost to follow-up (1.07, 0.81 to 1.42).

CONCLUSION

The risk factors for loss to 5-year follow-up were comparable to those reported in other population-based studies and included younger age, male gender, current smoking, lower educational level and higher symptom prevalence and morbidity. We found that exposure to VGDF, irritating and LMW agents can be risk factors associated with loss to follow-up. Results suggest that loss to follow-up did not affect estimates of occupational exposure as a risk factor for respiratory symptoms.

Optimal Use of Physical Centric Relation Records for Digital Workflows

Correctly articulated dental casts are essential for certain dental treatment. Articulation can be traditional: using a physical articulator; digital: using a physical articulator followed by 3D scanning, or virtual: using 3D scanning and software to articulate scans without initial physical articulation. This study compared the precision of traditional articulation, using physical centric relation records and an articulator and virtually, by digitally aligning scans of the casts and record. Articulated casts and centric relation records were obtained. 12 record pairs were recorded from the articulated casts. Virtual method: all records were scanned, unclamped, in a custom laboratory scanner. The casts were aligned to each scanned record to create virtual articulations. Traditional method: each record was used to physically articulate the casts. Each articulation was recorded using an intraoral scanner. The mean inter-arch separation between three key-points on each cast-pair were used to determine differences in occlusal separation in three anatomical directions, and precision of methods. Traditional articulations: standard deviations in key-point distance never exceeded 0.102mm. The virtual equivalent was 0.059mm. Statistically significant differences (p⟨0.05) between all anteroposterior separation distances were found between the methods, and in three of six lateral/vertical separations. Virtual articulation was significantly more precise than traditional articulation.

Cardiac Autonomic Activity in Commercial Aircrew During an Actual Flight Duty Period

BACKGROUND: The work schedules of airline crewmembers include extended workdays, compressed work periods, and limited time for recovery, which may lead to cardiovascular strain and fatigue. The aim of this study was to evaluate changes in heart rate variability (HRV) during work and sleep, and with respect to work characteristics and breaks.METHODS: We followed 49 airline crewmembers during four consecutive workdays of ≥39 h. Data included HRV measurements, a questionnaire, and sleep/work diaries. HRV parameters include root mean square of successive differences (RMSSD), standard deviation of the normal beat-to-beat differences (SDNN), and the low and high frequency ratio (LF/HF).RESULTS: The results indicate higher levels of cardiovascular strain on the 4th compared to the 1st workday, most prominent among cabin crewmembers. In this group, we observed indications of decreased cardiovascular strain by increasing duration of sleep, demonstrated by increased RMSSD (B = 2.7, 95% CI 1.6, 3.8) and SDNN (B = 4.4, 95% CI 3.0, 5.7), and decreased LF/HF (B = -0.2, 95% CI, -0.4,-0.01). Similarly, longer duration of breaks was associated with lower cardiovascular strain, indicated by increased RMSSD (B = 0.1, 95% CI 0.03, 0.1) and SDNN (B = 0.1, 95% CI 0.1, 0.1). Among pilots, increased LF/HF indicated higher cardiovascular strain in those who often or always reported of high workload (B = 4.3, 95% CI 2.3, 6.3; and B = 7.3, 95% CI 3.2, 11.4, respectively).DISCUSSION: The results support the contention that the studied work period increases cardiac strain among airline crew. Work characteristics, breaks, and sleep are associated with changes in HRV.Goffeng EM, Nordby K-C, Tarvainen M, Järvelin-Pasanen S, Wagstaff A, Skare Ø, Lie J-A. Cardiac autonomic activity in commercial aircrew during an actual flight duty period. Aerosp Med Hum Perform. 2019; 90(11):945-952.

Risk of Fatigue Among Airline Crew During 4 Consecutive Days of Flight Duty

BACKGROUND: Airline crew are being exposed to extended workdays and compressed work periods, with quick returns between duties, implying a heightened physiological and psychological strain that may lead to sleep deprivation and fatigue. The aim of the study was assessment of the effect of an extended day of flight duty and a compressed work week with regard to recovery, cumulative fatigue, and neurobehavioral performance.METHODS: We followed 18 pilots and 41 cabin crewmembers during four consecutive days of flight duty, comprising a total of ≥ 39 h, where the first day was ≥ 10 h. Information on demographics, work characteristics, health status, and physical activity was collected at baseline. Subjects completed logs for the first and fourth workday, including the Samn-Perelli Fatigue Checklist at three time points during these workdays. Two computer-based neurobehavioral tests were completed the evening prior to the first shift, and after the first and the fourth day of the work period.RESULTS: Number of flight sectors during the work period was 10-20. Self-reported fatigue levels increased during the workdays. Neurobehavioral test-scores did not deteriorate. The effects of each additional flight sector during the work period was elevated reaction times (RT) both among cabin crewmembers (B = 5.05 ms, 95% CI 0.6, 9.5) and pilots (B = 4.95 ms, 95% CI 0.4, 9.5). Precision was unaffected.DISCUSSION: Airline pilots and cabin crewmembers seem to obtain satisfactory sleep before and during the period of 4 consecutive days. The association between multiple flight sectors and increased fatigue supports previous findings.Goffeng EM, Wagstaff A, Nordby K-C, Meland A, Goffeng LO, Skare Ø, Lilja D, Lie J-AS. Risk of fatigue among airline crew during 4 consecutive days of flight duty. Aerosp Med Hum Perform. 2019; 90(5):466-474.

Impact of Mindfulness Training on Physiological Measures of Stress and Objective Measures of Attention Control in a Military Helicopter Unit

Objective: This study sought to determine if mindfulness training (MT) has a measurable impact on stress and attentional control as measured by objective physiological and psychological means.

Background: Periods of persistent, intensive work demands are known to compromise recovery and attentional capacity. The effects of 4-month MT on salivary cortisol and performance on 2 computer-based cognitive tasks were tested on a military helicopter unit exposed to a prolonged period of high workload.

Methods: MT participants were compared to a wait list control group on levels of saliva cortisol and performance on a go–no go test and a test of stimulus-driven attentional capture. Participants also reported mental demands on the go–no go test, time of wakeup, sleep duration, quality of sleep, outcome expectancies, physical activity level, self-perceived mindfulness, and symptoms of depression and anxiety.

Results: The results from a mixed between–within analysis revealed that the MT participants compared to the control group had a larger pre to post increase in high- and low-cortisol slopes, and decrease in perceived mental demand imposed by the go–no go test.

Conclusion: MT alleviates some of the physiological stress response and the subjective mental demands of challenging tasks in a military helicopter unit during a period of high workload.

CT examination of the pericardium and lungs in helicopter pilots exposed to vibration and noise

INTRODUCTION

Helicopter pilots are exposed to whole body vibration and noise in their working environment. Some researchers have found that kinetic energy from both noise and vibration is believed to affect pericardial thickness and lead to pulmonary fibrosis, known as vibroacoustic disease. The aim of this project was to determine whether we could discover similar findings in a selection of helicopter pilots.

METHODS

A case control study where 27 helicopter pilots were compared to an age-matched control group of typical office workers was conducted. High resolution CT scanning of the thorax was used as the diagnostic method. Two medical radiologists interpreted the images independently, blinded to whether the subjects were pilots or from the control group.

RESULTS

There were no signs of pericardial thickening or significant lung fibrosis formations in either of the groups. The average pericardium thickness for the helicopter group was 1.38 mm, SD = 0.54 mm, and for the control group: 1.37 mm, SD = 0.33 mm. There was no significant correlation between pericardium thickness and flight hours or age.

DISCUSSION

The average pericardial thickness values for the helicopter and the age-matched control groups were almost identical. The results are within normal limits and comparable to an American study where 21 normal individuals were measured to 1.2 mm +/- 0.8 mm in an average of 26 different points by using trans-esophageal echocardiography.

CONCLUSION

On the basis of the CT scans, our findings do not support the existence of vibroacoustic disease, where pericardial thickening is the most prominent sign.

A helicopter flight does not induce significant changes in systemic biomarker profiles

Whole-body vibration and noise are inherent characteristics of helicopter operations. The helicopter pilot is affected by vibration from both low-frequency noise and mechanical vibration sources. The way this energy is transmitted to different tissues and organs depends on intensity, frequency and resonance phenomena within the body. Whole-body vibration is known to affect the muscular and skeletal system in the lower part of the spine, but less is known about the response at the cellular level to this stimulation. In some studies, chronic pathological changes have been described in different types of tissue in people exposed to low-frequency noise and vibration. The aim of the present study was to investigate possible cellular reactions to acute exposure to low-frequency noise and vibration in a helicopter. Thirteen healthy males aged 38 (18-69) years were subjected to a 3.5 h helicopter flight in a Westland Sea King Rescue helicopter. Blood tests taken before and after the flight were analysed for more than 40 parameters, including acute phase reactants, markers of leucocyte and platelet activation, complement and hemostasis markers, as well as a broad panel of cytokines, chemokines, growth factors and cell adhesion molecules. The subjects served as their own controls. With the exception of an increase in vascular cell adhesion molecule-1 (VCAM-1) during the flight, no statistically significant changes in the biomarkers were found after controlling for diurnal variation in the control blood tests, which were observed independently of the helicopter flight. In conclusion, one helicopter flight does not induce measurable changes in systemic biomarkers.

China, Hong Kong and Taiwan, Health Systems of

This article describes how health care has been and is currently financed, organized, and delivered in China, Hong Kong, and Taiwan. Each system's performance is assessed on the equity and efficiency axes in terms of how well it deals with important market failures. We conclude by drawing comparative lessons and showing how policymakers are trying or might attempt to rise up to and overcome key challenges.

[Reasons for medical disqualification of Norwegian commercial pilots]

BACKGROUND

The aim of this study is to present the reasons for medical disqualification (grounding) of Norwegian commercial pilots over a twenty-year period. We have also examined the issues of whether a change has taken place in the disease spectrum and to which extent new regulations have influenced aeromedical decision making.

MATERIAL AND METHODS

The material is collected from the aeromedical section's archive. Files on all grounded pilots have been reviewed and classified by age group and diagnosis and grounding rates have been calculated.

RESULTS

From the study population comprising 48,229 pilot-years, 275 pilots were permanently grounded, i.e. an average grounding rate of 5.7 per 1000 pilot-years.

INTERPRETATION

Over this twenty-year period, the grounding rate based on cardiovascular disease fell; this may be explained by better treatment or more lenient requirements. In the diagnostic categories neurologic, musculoskeletal and psychiatric diseases the grounding rates went up. This cannot be attributed to more stringent health requirements, but possibly to the attitudes of pilots, who have become more critical of their working environment.

A study of the effects of using different cerebral perfusion pressure (CPP) thresholds to quantify CPP "secondary insults" in children

Little is known about the incidence of secondary insults, particularly cerebral perfusion pressure insults, in children. The objectives of this study were to assess the duration of CPP insults at three different thresholds in children and to relate CPP insults to outcome. Eighteen children (age < 16, median & mean 8 years) admitted to the Neurointensive Care Unit who had ICP, MAP and CPP continuously monitored were studied. Using the Edinburgh secondary insult analysis program, data was scanned for CPP insults at three different thresholds: CPP < 70 mmHg, < 60 mmHg and < 50 mmHg. Outcome was assessed using the Glasgow Outcome Scale. Thirty percent of the time CPP was between 60 and 70 mmHg, 21% of the time CPP was between 50 and 60 mmHg and 8% of the time the CPP was less than 50 mmHg. Compared with adults, there was more than twice the incidence of CPP insults in all threshold groups. BP remained relatively stable above 70 mmHg across all three CPP threshold groups. However, ICP increased slightly on average from about 13-->17 mmHg when CPP decreased from the < 70 to < 60 mmHg group (p < 0.001). There was a marked increase in ICP to greater than 30 mmHg on average in the CPP < 50 mmHg group (p < 0.001). CPP insults less than 70, 60 and 50 mmHg do occur commonly in children, a larger dataset and possibly longer term follow up measures will be needed to identify potentially treatable physiological factors most effecting the outcome of children.

Economics, health and development: some ethical dilemmas facing the World Bank and the international community

The World Bank is committed to "work[ing] with countries to improve the health, nutrition and population outcomes of the world's poor, and to protect[ing] the population from the impoverishing effects of illness, malnutrition and high fertility".(1) Ethical issues arise in the interpretation of these objectives and in helping countries formulate strategies and policies. It is these ethical issues--which are often not acknowledged by commentators--that are the subject of this paper. It asks why there should be a focus on the poor, and explores the link between improving the health of the poor, and reducing health inequalities between the poor and better-off. It discusses difficult ethical issues at both the global level (including debt relief and the link between country ownership and donor commitment) and the country level (including user fees and whether providing assistance to the non-poor may in the long run be a way of helping the poor).

Income inequality and health: what does the literature tell us?

This paper reviews the large and growing body of literature on the apparently negative effects of income inequality on population health. Various hypotheses are identified and described that explain the empirically observed association between measures of income inequality and population health. We have concluded that data from aggregate-level studies of the effect of income inequality on health, i.e. studies at the population and community (e.g. state) levels, are largely insufficient to discriminate between competing hypotheses. Only individual-level studies have the potential to discriminate between most of the advanced hypotheses. The relevant individual-level studies to date, all on U.S. population data, provide strong support for the "absolute-income hypothesis," no support for the "relative-income hypothesis," and little or no support for the "income-inequality hypothesis." Results that provide some support for the income-inequality hypothesis suggest that income inequality at the state level affects mainly the health of the poor. There is only indirect evidence for the "deprivation hypothesis," and no evidence supports the "relative-position hypothesis." Overall, the absolute-income hypothesis, although > 20 years old, is still the most likely to explain the frequently observed strong association between population health and income inequality levels.

Equity in the delivery of health care in Europe and the US

This paper presents a comparison of horizontal equity in health care utilization in 10 European countries and the US. It does not only extend previous work by using more recent data from a larger set of countries, but also uses new methods and presents disaggregated results by various types of care. In all countries, the lower-income groups are more intensive users of the health care system. But after indirect standardization for need differences, there is little or no evidence of significant inequity in the delivery of health care overall, though in half of the countries, significant pro-rich inequity emerges for physician contacts. This seems to be due mainly to a higher use of medical specialist services by higher-income groups and a higher use of GP care among lower-income groups. These findings appear to be fairly general and emerge in countries with very diverse characteristics regarding access and provider incentives.

Socioeconomic inequalities in child mortality: comparisons across nine developing countries

This paper generates and analyses survey data on inequalities in mortality among infants and children aged under five years by consumption in Brazil, Côte d'Ivoire, Ghana, Nepal, Nicaragua, Pakistan, the Philippines, South Africa, and Viet Nam. The data were obtained from the Living Standards Measurement Study and the Cebu Longitudinal Health and Nutrition Survey. Mortality rates were estimated directly where complete fertility histories were available and indirectly otherwise. Mortality distributions were compared between countries by means of concentration curves and concentration indices: dominance checks were carried out for all pairwise intercountry comparisons; standard errors were calculated for the concentration indices; and tests of intercountry differences in inequality were performed.

First observations of the safety and tolerability of a competitive antagonist to the glutamate NMDA receptor (CGS 19755) in patients with severe head injury

A dose escalation, safety, and tolerability study of a competitive antagonist to the N-methyl-D-aspartate (NMDA) glutamate receptor (CGS 19755, Selfotel) in patients with severe head injury is reported. The drug was administered i.v. on two separate occasions, 24 h apart, to 31 patients. The dosage was escalated during the study from 1 mg/kg to 6 mg/kg. Continuous monitoring of mean arterial pressure (MABP), intracranial pressure (ICP), cerebral pressure (CPP), arterial oxygen saturation (SaO2), jugular bulb oxygen saturation (SjO2), and temperature was performed. Intermittent measurements of middle cerebral artery (MCA) velocity via transcranial Doppler ultrasound were also made 2 h before drug administration and continued for 24 h after dosing. The patients were ventilated and sedated with morphine and either midazolam or propofol. There were no behavioral changes during or after administration of the drug, and disorders of perception were reported by only three subjects, several days after relatively low doses; these were transient and were not recalled at later follow-up. We did not detect consistent changes in any of the hemodynamic parameters monitored, up to dosages of 3 mg/kg. After higher doses, some patients showed changes in MABP, ICP, and temperature during the 4 to 8-h period following the first bolus of the drug, with a return toward baseline afterwards. No consistent, serious, adverse events were considered to be due to drug effects, and death, in the one patient who died, was due to the effects of the injury. Our results indicate that CGS 19755 may be given at dosages < or = 3-5 mg/kg with acceptable safety and tolerability in stable, ventilated, and carefully monitored severe head-injured patients.

The redistributive effect of health care finance in twelve OECD countries

The OECD countries finance their health care through a mixture of taxes, social insurance contributions, private insurance premiums and out-of-pocket payments. The various payment sources have very different implications for both vertical and horizontal equity and on redistributive effect which is a function of both. This paper presents results on the income redistribution consequences of the health care financing mixes adopted in twelve OECD countries by decomposing the overall income redistributive effect into a progressivity, horizontal inequity and reranking component. The general finding of this study is that the vertical effect is much more important than horizontal inequity and reranking in determining the overall redistributive effect but that their relative importance varies by source of payment. Public finance sources tend to have small positive redistributive effects and less differential treatment while private financing sources generally have (larger) negative redistributive effects which are to a substantial degree caused by differential treatment.

Equity in the finance of health care: some further international comparisons

This paper presents further international comparisons of progressivity of health care financing systems. The paper builds on the work of Wagstaff et al. [Wagstaff, A., van Doorslaer E., et al., 1992. Equity in the finance of health care: some international comparisons, Journal of Health Economics 11, pp. 361-387] but extends it in a number of directions: we modify the methodology used there and achieve a higher degree of cross-country comparability in variable definitions; we update and extend the cross-section of countries; and we present evidence on trends in financing mixes and progressivity.

Early 1H magnetic resonance spectroscopy of acute head injury: four cases

In an attempt to examine in vivo the early metabolic consequences of severe acute head injury, 1H MRS was performed in four patients from 8 to 25 h (mean 15 h) following trauma. In three of these patients, decompressive surgery was performed 4-5 h prior to the MRS. High levels of lactate (area of lactate peak >50% of the mean areas of the NAA, choline-containing, and creatine-containing compound peaks) were found at 8 h posttrauma in the one patient who was not operated on and at 10 h posttrauma in one of the patients who underwent surgery. In the other two postoperative patients, at 18 and 25 h after trauma, lactate levels were found to be low (lactate peak <20% of the mean area of the other three peaks). In the one patient who had a follow-up at 6 days and who had the largest initial lactate levels, these remained high. These findings suggest that high levels of lactate may not be an inevitable consequence of severe head injury and that similar MRS studies should be performed on each individual patient before therapies to reduce lactate are considered. There appeared to be no correlation between the relative amounts of lactate and outcome.

Progressivity, horizontal equity and reranking in health care finance: a decomposition analysis for The Netherlands

This paper employs the method of Aronson et al. (1994) to decompose the redistributive effect of the Dutch health care financing system into three components: a progressivity component, a classical horizontal equity component and a reranking component. Results are presented for the health care financing system as a whole, as well as for its constituent parts. A final section sets out to uncover the relative importance (in terms of their effects on progressivity, horizontal equity and reranking) of the key institutional features of one component of the Dutch system-the AWBZ social insurance scheme.

Income-related inequalities in health: some international comparisons

This paper presents evidence on income-related inequalities in self-assessed health in nine industrialized countries. Health interview survey data were used to construct concentration curves of self-assessed health, measured as a latent variable. Inequalities in health favoured the higher income groups and were statistically significant in all countries. Inequalities were particularly high in the United States and the United Kingdom. Amongst other European countries, Sweden, Finland and the former East Germany had the lowest inequality. Across countries, a strong association was found between inequalities in health and inequalities in income.

Measuring inequalities in health in the presence of multiple-category morbidity indicators

This paper considers the problems which arise in seeking to measure socioeconomic inequalities in health when the health indicator is a categorical variable, such as self-assessed health. It shows that the standard approach--which involves dichotomizing the categorical variable--is unreliable. The degree of measured inequality is found to depend on the cut-off point chosen and the choice of cut-off point to affect the conclusions one can reach about trends in or differences in health inequality. The paper goes on to propose an alternative approach which involves constructing a latent health variable and then measuring inequalities in this latent variable by means of a variant of the health concentration curve.

Equity and equality in health and health care

This paper explores four definitions of equity in health care: equality of utilization, distribution according to need, equality of access, and equality of health. We argue that the definitions of 'need' in the literature are inadequate and propose a new definition. We also argue that, irrespective of how need and access are defined, the four definitions of equity are, in general, mutually incompatible. In contrast to previous authors, we suggest that equality of health should be the dominant principle and that equity in health care should therefore entail distributing care in such a way as to get as close as is feasible to an equal distribution of health.

QALYs (quality-adjusted life-years) versus HYEs (healthy years equivalents)

This paper explores the claim that QALYs are liable to misrepresent consumer preferences and hence lead to decision-makers choosing options which are not those preferred by the public. It also considers the claim that HYEs do not suffer from this defect. We argue that none of the examples offered to date demonstrate the alleged tendency of QALYs to misrepresent preferences. We also show that HYEs are identical to QALY scores obtained from a time tradeoff experiment and therefore that the assumptions about preferences underlying HYEs are just as restrictive as those underlying TTO-based QALYs.

The demand for health: an empirical reformulation of the Grossman model

Previous tests of Grossman's model of the demand for health have been based on Grossman's own empirical formulation. This paper argues that this formulation fails to capture the dynamic character of the model. It proposes an alternative formulation, which appears to be more consistent with Grossman's theoretical model and which may also explain the apparent rejections of the model by the data in the author's earlier empirical work. The paper also presents some empirical results obtained using the new formulation, which are, on the whole, consistent with the predictions of Grossman's theoretical model.

Equity and efficiency in Italian health care

Health care finance and provision in Italy is unusual by international standards: public financing relies heavily on both general taxation and social insurance, and although the vast majority of expenditure is publicly financed, the majority of care is provided by the private sector. The system suffers, however, from a chronic failure to control expenditures and its record on perinatal and infant mortality is poor. Hospitals in Italy have a low bed-occupancy rate by international standards and the per diem system of reimbursing private hospitals encourages unduly long stays. Costs per inpatient day are high by international standards, but costs per admission are close to the OECD average. Ambulatory care costs are extremely low, but this appears to be due to the fact that GPs see so many patients that their role is inevitably mainly administrative. Consumption of medicines is extremely high, but because the cost per item is low, expenditure per capita is not unduly high. Despite the emphasis on social insurance, the financing system appears to be progressive. There is evidence of inequalities in health in Italy, and some evidence that health care is not provided equally to those in the same degree of need.

Equity in the delivery of health care: some international comparisons

This paper presents the results of an eight-country comparative study of equity in the delivery of health care. Equity is taken to mean that persons in equal need of health care should be treated the same, irrespective of their income. Two methods are used to investigate inequity: an index of inequity based on standardized expenditure shares, and a regression-based test. The results suggest that inequity exists in most of the eight countries, but there is no simple one-to-one correspondence between a country's delivery system and the degree to which persons in equal need are treated the same.

Equity in the finance of health care: some international comparisons

This paper presents the results of a ten-country comparative study of health care financing systems and their progressivity characteristics. It distinguishes between the tax-financed systems of Denmark, Portugal and the U.K., the social insurance systems of France, the Netherlands and Spain, and the predominantly private systems of Switzerland and the U.S. It concludes that tax-financed systems tend to be proportional or mildly progressive, that social insurance systems are regressive and that private systems are even more regressive. Out-of-pocket payments are in most countries an especially regressive means of raising health care revenues.

On the measurement of horizontal inequity in the delivery of health care

This paper offers a critical appraisal of the various methods used to date to investigate inequity in the delivery of health care. It concludes that none of the methods used to date is particularly well equipped to provide unbiassed estimates of the extent of inequity. It also concludes that Le Grand's (1978) approach is likely to point towards inequity favouring the rich even when none exists. The paper offers an alternative approach, which builds on the approaches to date but seeks to overcome their deficiencies.

On the measurement of horizontal inequity in the delivery of health care

This paper offers a critical appraisal of the various methods used to date to investigate inequity in the delivery of health care. It concludes that none of the methods used to date is particularly well equipped to provide unbiassed estimates of the extent of inequity. It also concludes that Le Grand's (1978) approach is likely to point towards inequity favouring the rich even when none exists. The paper offers an alternative approach, which builds on the approaches to date but seeks to overcome their deficiencies.

QALYs and the equity-efficiency trade-off

As the volume of research on quality-adjusted life years (QALYs) has increased, concern has begun to be expressed about the equity aspects of resource allocation decisions based on the results of this research. This paper suggests that a common theme running through the criticisms of the QALY approach is a concern about inequality. It also suggests that the method for incorporating distributional concerns which is currently being pursued by advocates of the QALY approach will only ever capture concerns other than a concern about inequality. The paper suggests a method for incorporating both sets of concerns into resource allocation decisions.

On the measurement of inequalities in health

This paper offers a critical appraisal of the various methods employed to date to measure inequalities in health. It suggests that only two of these--the slope index of inequality and the concentration index--are likely to present an accurate picture of socioeconomic inequalities in health. The paper also presents several empirical examples to illustrate of the dangers of using other measures such as the range, the Lorenz curve and the index of dissimilarity.

Uncertainty and the demand for medical care

This paper provides an analysis of the effects of uncertainty on the demand for medical care using a simplified version of Grossman's human capital model of the demand for health. Two types of uncertainty are analysed: the uncertainty surrounding the incidence of illness and the uncertainty surrounding the effectiveness of medical care. In the first the consumer's basic level of health is assumed to be a random variable; in the second the effectiveness of medical care is assumed to be random. Comparative static results are reported indicating the effects on the demand for medical care of both increases in the means of these distributions and mean-preserving spreads of the distributions.

Economic aspects of illicit drug markets and drug enforcement policies

This paper reviews the economics literature on illicit drug markets and drug enforcement policies. The first part of the paper examines the problems involved in establishing the parameters of the illicit market. The second part of the paper examines the contribution economics can make to the evaluation of drug enforcement policies: the discussion covers the determination of both the appropriate level of enforcement expenditure and the appropriate mix of policy measures.

Econometric studies in health economics. A survey of the British literature

This paper provides a survey of British applied econometric work in the field of health economics. As well as reviewing the literature, it suggests some avenues for future research. It covers six main areas: the supply of health care; the demand for health care; non-medical influences on health; market and non-price rationing; evaluation of health care systems; and planning, budgeting and monitoring mechanisms.

Uncertainty, inequalities in health and the demand for health

As it has become increasingly recognized that inequalities in health stem more from inequalities in wealth, rather than from inequalities in access to medical care, economists have begun to suggest that Michael Grossman's model of the demand for health may be a useful analytical framework for investigating the issue. Ironically, the more popular of Grossman's two submodels--the 'pure-investment' model--provides little by way of insights into the relationship between inequalities in wealth and inequalities in health. In common with other pure investment models of human capital formation, Grossman's model predicts that an individual's health investment decisions at each stage in the lifecycle will be independent of his initial wealth. This paper shows that if uncertainty is introduced into the model, this result no longer holds. It also shows that if individuals display decreasing absolute risk aversion, wealthier individuals will invest more in health capital than individuals who start life with relatively small stocks of financial capital.