Depression and risk of sudden cardiac death after acute myocardial infarction: testing for the confounding effects of fatigue

OBJECTIVES

This study examined the impact of depressive symptoms and social support on 2-year sudden cardiac death (SCD) risk, controlling for fatigue symptoms.

METHODS

Myocardial infarction (MI) patients (N = 671) participating in the Canadian Amiodarone Myocardial Infarction Arrhythmia Trial completed measures of depression, hostility, and social support.

RESULTS

After controlling for significant biological predictors, psychosocial predictors of increased SCD risk in the survival analysis were greater social network contacts (RR = 1.04; 95% CI = 1.01-1.06; p < .007), lower social participation (RR = 0.98; 95% CI = 0.96-1.00; p < .05), and, in placebo-treated patients, elevated depressive symptoms (RR = 2.45; 95% CI = 1.14-5.35; p < .02). Fatigue was associated with SCD (RR = 1.31; 95% CI = 1.11-1.53; p < .001), and, when included in the model, diminished the influence of depression (RR = 1.73; 95% CI = 0.75-3.98; p = .20). When the cognitive-affective depressive symptoms were examined separately from somatic symptoms, there was a trend for an association between cognitive-affective symptoms and SCD in placebo-treated patients after controlling for fatigue (RR = 1.09; 95% CI = 0.99-1.19, p < .06).

CONCLUSIONS

Symptoms of depression and fatigue overlap in patients with MI. The trend for the cognitive-affective symptoms of depression to be associated with SCD risk, even after controlling for dyspnea/fatigue, suggests that the association between depression and mortality after AMI cannot be entirely explained as a confound of cardiac-related fatigue. The independent contribution of social participation suggests a role of both depressive symptomatology and social factors in influencing mortality risk after MI.

Do people value their own future health differently from others' future health?

The purpose of this study was to investigate whether time preferences for own health are the same as time preferences for others' health. A random sample of the general public was sent a postal questionnaire containing six choices between ill health in the near future and ill health in the further future. They were asked to indicate the maximum duration of more distant ill health they would be willing to accept in return for a specified delay in the onset of the period of ill health. For half of the sample the questions were set in the context of their own health and for the other half in terms of others' health. The median implied discount rates were not statistically different, 0.061 for own health and 0.062 for others' health. A multilevel analysis of the determinants of these implied discount rates provided additional evidence of the similarity of time preferences for own health and others' health.

What price information? Modelling threshold probabilities of fetal loss

This paper is an extension of previous work in which an alternative method of measuring the benefits of antenatal screening was proposed. The method is based on the elicitation of threshold probabilities of fetal loss at which women would be indifferent between having and not having an amniocentesis for the prenatal diagnosis of fetal abnormalities. The aim of this paper is to extend the previous work by modelling the preferences of a larger sample of women and investigating the consistency and validity of their responses. The threshold probabilities are elicited using standard gambles and modelled using Tobit estimation. The results indicate that it is possible to model these probabilities in this way and that it is possible to obtain a high degree of consistency in response to standard gamble questions. While establishing the validity of the responses is more difficult there is some evidence that the technique can provide valid responses.

Poor adherence to placebo or amiodarone therapy predicts mortality: results from the CAMIAT study. Canadian Amiodarone Myocardial Infarction Arrhythmia Trial

OBJECTIVE

This study examined the relationship between adherence, mortality, and psychosocial factors.

METHODS

Subjects were 1141 patients participating in the Canadian Amiodarone Myocardial Infarction Arrhythmia Trial. Poor adherence to study medication (amiodarone or placebo), measured by pill count over 2 years, was defined as the lower 20th percentile of the pill count distribution. Predictors of adherence were also studied and included demographic and cardiac variables and, in a subset of participants (N = 671), measures of depression, distress, hostility, and social support.

RESULTS

In survival analysis controlling for cardiac and demographic variables, poor adherence in the placebo and amiodarone groups was associated with an increased risk of sudden cardiac death (relative risk (RR) = 2.11, 95% confidence interval (CI) = 1.03-4.56, p < .05; and RR = 3.15, 95% CI = 1.34-7.44, p < .01, respectively), total cardiac mortality (RR = 2.04, 95% CI = 1.12-3.72, p < .02; and RR = 2.49, 95% CI = 1.32-4.72, p < .01, respectively), and all-cause mortality (RR = 2.25, 95% CI = 1.27-3.97, p < .001; and RR = 2.34, 95% CI = 1.32-4.17, p < .004, respectively). Logistic regression analysis identified two predictors of poor adherence to placebo: age > 70 years (odds ratio = 2.18, 95% CI = 1.11-4.29, p < .03) and social activities in the month before the index heart attack (odds ratio = 1.02, 95% CI = 1.00-1.04, p < .05).

CONCLUSIONS

Poor adherence is associated with a greater risk of mortality. The relationship between adherence and social activities suggests a higher motivation to adhere to treatment in individuals more engaged in enjoyable activities.

Nurse practitioner support for transfusion in patients with haematological disorders in hospital and at home

We prospectively studied the effects of dedicating a nurse to manage the provision of blood product support in a hospital haematology unit and at home to 45 patients with haematological disorders requiring regular transfusion. During the study 335 home blood tests, 65 home platelet transfusions and 155 hospital transfusions were managed by the nurse who organized the whole transfusion process, made home visits for blood tests and platelet transfusions and arranged hospital visits for red cell transfusions. Two hundred clinic visits and 65 day hospital attendances were avoided. The nurse-led service resulted in a significant reduction in the waiting time from admission to transfusion and in the total length of in-patient stay. The importance of and satisfaction with different aspects of the care of the transfusion process assessed by a ranking questionnaire showed improved satisfaction scores for all aspects of care. Preference for home blood sampling instead of hospital increased from 24% before to 100% after intervention. We have shown that a dedicated transfusion nurse provides a quality service between hospital and home that is greatly appreciated by patients requiring regular transfusions.

Absence of certainty is not synonymous with absence of risk

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Impact of a case management protocol for childhood pneumonia in a rural Zambian hospital

This study aimed to assess the impact of adopting the WHO case management protocol for childhood pneumonia in a district hospital in rural Zambia. The subjects were children under 5 years of age with a diagnosis of pneumonia, admitted in the 9-month period following introduction of the WHO protocol. Management and outcome were compared with a historical control group admitted during the same period in the previous year. There were 158 children in the intervention group and 135 controls with similar age and sex distribution. Both groups were malnourished (mean weight-for-age Z score in subjects = -1.91, in controls = -1.83). There was no significant difference in the numbers receiving parenteral antibiotics or supplementary fluids in each group. However, children in the intervention group were significantly more likely to receive oxygen (odds ratio 4.7, 95% confidence interval 2.8-8.1, p < 0.0001). Mortality was significantly greater in the control group (case fatality rate, 25%) compared with the intervention group (case fatality rate, 15%; chi 2 = 4.6; p = 0.032). The introduction of the WHO protocol for management of childhood pneumonia and training of staff in its use was accompanied by a fall in mortality from this condition in a rural hospital. The improved survival rate may be related to the more frequent use of oxygen.

Establishing patient preferences for blood transfusion support: an application of conjoint analysis

OBJECTIVE

To develop a method of determining the relative importance of waiting time and location of care for patients with haematological disorders requiring red cell transfusion. Such information is particularly relevant when evaluating interventions that affect patient well-being (e.g. by changing waiting time and location) but do not affect health outcomes.

METHODS

Conjoint analysis is used to assess the relative importance of waiting time and location with respect to pre-transfusion testing and red cell transfusion. Compensation is also included as an attribute in order to estimate the monetary value of changes in waiting time and location.

RESULTS

Waiting time and location are important attributes in the provision of pre-transfusion testing and red cell transfusion. Compensation is not an important attribute. On average patients are willing to wait an additional 45 minutes in order to have pre-transfusion testing in their own home and an additional 35 minutes in order to receive red cell transfusions in their preferred location.

CONCLUSION

The relative importance of waiting time and location of care was established. However, it was not possible to assign monetary values since compensation was not an important attribute for these respondents. The paper highlights the scope for using conjoint analysis to analyse the non-health benefits that may result from changes in the delivery of care.

A framework for the economic evaluation of telemedicine

This paper describes the economic issues associated with the introduction of telemedicine systems and the main challenges to their evaluation. An approach to the economic evaluation of telemedicine is described based on a cost-consequence framework. The paper links these costs and consequences more formally within a set of evaluative questions which in turn forms the basis for an economic model for evaluating telemedicine. By outlining the key questions, a number of issues relevant to the evaluation of telemedicine are identified and considered. The main challenges to the economic evaluation of telemedicine include: constantly changing technology; lack of appropriate study design to manage the frequently inadequate sample sizes; inappropriateness of the conventional techniques of economic evaluation; and the valuation of health and non-health outcomes. The present study addresses these challenges and suggests ways of advancing the techniques for the economic evaluation of telemedicine.

Modeling acute and chronic toxicity of nonpolar narcotic chemicals and mixtures to Ceriodaphnia dubia

The response of the daphnid Ceriodaphnia dubia to six widely used industrial chemicals acting through nonpolar narcosis and a mixture was determined. Toxicological effect levels were based on reasonably steady-state, measured concentrations. Reproductive IC50S were 149 microM benzene, 82 microM trichloroethylene, 35 microM toluene, 31 microM ethylbenzene, 26 microM m-xylene, and 4 microM tetrachloroethylene. A QSAR describing 2-day LC50S as a function of log Kow accounted for 90.97% of the variation in response across chemical. A similar QSAR for chronic effects on reproduction accounted for 78.92%. Mixtures of benzene, trichloroethylene, and toluene had effects at concentrations below their individual LOELs. Observed effects of 20/24 mixtures tested fell within the 95% prediction interval for a concentration-addition model of joint action derived from tests with individual components. However, the observed response differed significantly from the predictive relationship. In general, the predictive relationship overestimated mixture toxicity. Fitted relationships reduced observed error by as much as 82% compared to the predictive model.

Maintaining the habitable condition of the planet: balancing technological and ecosystem services

Infinite growth cannot continue on a finite planet. One reason is that human society is dependent on a life-support system that is both technological and ecological. Ecosystem services (including regeneration of topsoil, maintenance of atmospheric gas balance, cleansing of water, and maintenance of a genetic library to meet climate changes, whether induced by humans or by nature) are provided by nature. In meeting the perceived needs of human society, the ability of the ecological life-support system to deliver services may be compromised. To prevent this, human society will have to undergo major changes in behavior. Change will be facilitated if a common sustainability paradigm is accepted to meet certain conditions and goals. The main goal is to provide human descendants with a habitable planet, and this entails protecting natural systems that provide necessary life-support functions. If this goal is accepted, then a number of supporting goals can be stated and the conditions necessary to meet these goals can be outlined.

Constant and decreasing timing aversion for saving lives

The traditional model of time preferences employed by economists is characterised by constant timing aversion. The available evidence suggests that this is not an appropriate assumption. This paper examines evidence for constant and decreasing timing aversion with respect to saving lives. Three discounting models are considered: the constant discounting model; the proportional discounting model; and the hyperbolic discounting model. Data collected from the general public are used to test the constant timing aversion model. Overall, the findings suggest that there is substantial evidence for decreasing timing aversion and against the constant timing aversion hypothesis.

Defining goals and conditions for a sustainable world

Sustainable development is being approached component by component--socioeconomic, sustainable agriculture, transportation, forestry, energy use, cities, and the like--but, leaving a habitable planet for future generations will require the development of a widely shared paradigm. Further, the paradigm should be ecological from a scientific point of view. This development will be facilitated by a discussion of goals and those conditions necessary to meet them. The presently shared paradigm is that economic growth is the cure for all of society's problems, such as poverty, overpopulation, environmental degradation, and the increasing gap between rich and poor. A paradigm shift from growth to sustainability might result either from suffering painful consequences of continuing to follow out-moded paradigms or by discussing what sort of ecosystems will be available to future generations. The purpose of this paper is to help initiate such a discussion.

Cost effectiveness of a mass media-led anti-smoking campaign in Scotland

OBJECTIVE

To evaluate the costs and outcomes associated with the Health Education Board for Scotland's general public anti-smoking campaign during the developmental stage and its first year of operation.

DESIGN

Cost information collected retrospectively was combined with prospectively collected effectiveness data.

SUBJECTS

A panel of 970 adults were recruited from a 1-in-10 random sample of adult callers to the telephone helpline (Smokeline). Those who smoked were subsequently interviewed at three weeks, six months, and one year follow up. Information on smoking status at one year and time spent as a non-smoker was available for 587 members of the panel.

MAIN OUTCOME MEASURES

Intermediate outcomes in the follow-up sample included a point prevalence and period prevalence measure of smoking cessation. Long-term outcomes were measured in terms of predicted reductions in mortality as a consequence of smoking cessation.

RESULTS

At the 12-month point, 9.88% of individuals in the follow-up sample reported themselves as non-smokers and as having given up for at least six months in the previous year. Estimates of the cost per life-year saved as a result of the campaign range from 304 pounds sterling to 656 pounds sterling.

CONCLUSIONS

Provided that the benefits of smoking cessation are broadly accurate, and the assumed level of quitting can be directly attributed to Smokeline, then this mass media-led anti-smoking campaign appears to have been cost effective.

Accelerated bacteriological evaluation in the management of lower respiratory tract infection in general practice

This paper examines the use of overnight accelerated bacteriological evaluation (ABLE) in the treatment of lower respiratory tract infection in general practice. The use of ABLE is compared with the empirical prescribing of antibiotics. The results indicate that ABLE leads to a saving in resource use without a deterioration in clinical outcome. In view of there being additional benefits, such as reduced antibiotic exposure and repeat visits, it is concluded that the use of ABLE in the way described would improve the management of lower respiratory tract infection in general practice.

Orchestrating the ecological and technological components of human society's life support system

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