Smaller hippocampal volume following sexual assault in women is associated with post-traumatic stress disorder.

OBJECTIVE: Exposure to sexual assault is a significant risk factor to develop post-traumatic stress disorder (PTSD) in females. The early neurobiological changes leading to the development of PTSD remain understudied and unclear in this population. METHODS: Participants were 27 adult females recruited within a month following exposure to sexual assault (T1) and 20 age-matched non-exposed controls. Among the victims, 10 participants met (PTSD+) and 15 did not meet (PTSD-) DSM-IV criteria for PTSD 6 months post-trauma (T2). At both visits, hippocampal and amygdala volumes were extracted from magnetic resonance imaging scans, and indices of total diurnal cortisol changes were derived from individual areas under the curve relative to the ground (AUCg). Measures at T1 were compared between groups at T1, measures at T2 between groups at T2, and measures at T1 between groups at T2. RESULTS: At T1, victims had significantly smaller bilateral hippocampal volumes, but not AUCg, than controls. At T2, neither hippocampal volume nor AUCg significantly differed among the groups. However, the PTSD+ group had significantly smaller hippocampal volumes at T1 than the control group, but not compared to the PTSD- group. CONCLUSIONS: This study indicates that having smaller hippocampal volumes is a risk factor to develop PTSD in females exposed to sexual assault.

Reduction in resource use with the misoprostol vaginal insert vs the dinoprostone vaginal insert for labour induction: a model-based analysis from a United Kingdom healthcare perspective.

BACKGROUND: In view of the increasing pressure on the UK's maternity units, new methods of labour induction are required to alleviate the burden on the National Health Service, while maintaining the quality of care for women during delivery. A model was developed to evaluate the resource use associated with misoprostol vaginal inserts (MVIs) and dinoprostone vaginal inserts (DVIs) for the induction of labour at term. METHODS: The one-year Markov model estimated clinical outcomes in a hypothetical cohort of 1397 pregnant women (parous and nulliparous) induced with either MVI or DVI at Southmead Hospital, Bristol, UK. Efficacy and safety data were based on published and unpublished results from a phase III, double-blind, multicentre, randomised controlled trial. Resource use was modelled using data from labour induction during antenatal admission to patient discharge from Southmead Hospital. The model's sensitivity to key parameters was explored in deterministic multi-way and scenario-based analyses. RESULTS: Over one year, the model results indicated MVI use could lead to a reduction of 10,201 h (28.9%) in the time to vaginal delivery, and an increase of 121% and 52% in the proportion of women achieving vaginal delivery at 12 and 24 h, respectively, compared with DVI use. Inducing women with the MVI could lead to a 25.2% reduction in the number of midwife shifts spent managing labour induction and 451 fewer hospital bed days. These resource utilisation reductions may equate to a potential 27.4% increase in birthing capacity at Southmead Hospital, when using the MVI instead of the DVI. CONCLUSIONS: Resource use, in addition to clinical considerations, should be considered when making decisions about labour induction methods. Our model analysis suggests the MVI is an effective method for labour induction, and could lead to a considerable reduction in resource use compared with the DVI, thereby alleviating the increasing burden of labour induction in UK hospitals.

Brain correlates of automatic visual change detection.

A number of studies support the presence of visual automatic detection of change, but little is known about the brain generators involved in such processing and about the modulation of brain activity according to the salience of the stimulus. The study presented here was designed to locate the brain activity elicited by unattended visual deviant and novel stimuli using fMRI. Seventeen adult participants were presented with a passive visual oddball sequence while performing a concurrent visual task. Variations in BOLD signal were observed in the modality-specific sensory cortex, but also in non-specific areas involved in preattentional processing of changing events. A degree-of-deviance effect was observed, since novel stimuli elicited more activity in the sensory occipital regions and at the medial frontal site than small changes. These findings could be compared to those obtained in the auditory modality and might suggest a "general" change detection process operating in several sensory modalities.

A major susceptibility locus for atopic dermatitis maps to chromosome 3q21.

Atopic dermatitis (eczema) is a chronic inflammatory skin disease with onset mainly in early childhood It is commonly the initial clinical manifestation of allergic disease, often preceding the onset of respiratory allergies. Along with asthma and allergic rhinitis, atopic dermatitis is an important manifestation of atopy that is characterized by the formation of allergy antibodies (IgE) to environmental allergens. In the developed countries, the prevalence of atopic dermatitis is approximately 15%, with a steady increase over the past decades. Genetic and environmental factors interact to determine disease susceptibility and expression, and twin studies indicate that the genetic contribution is substantial. To identify susceptibility loci for atopic dermatitis, we ascertained 199 families with at least two affected siblings based on established diagnostic criteria. A genome-wide linkage study revealed highly significant evidence for linkage on chromosome 3q21 (Zall=4.31, P= 8.42 10(-6)). Moreover, this locus provided significant evidence for linkage of allergic sensitization under the assumption of paternal imprinting (hlod=3.71,alpha=44%), further supporting the presence of an atopy gene in this region. Our findings indicate that distinct genetic factors contribute to susceptibility to atopic dermatitis and that the study of this disease opens new avenues to dissect the genetics of atopy.

The Association Between Tobacco Use and Risk of COVID-19 Infection and Clinical Outcomes in Sweden: A Population-Based Study.

Background: The association between tobacco use and COVID-19 is controversial. During the early course of the pandemic, limited testing prevented studying a wide spectrum of clinical manifestations. Objective: To examine the potential causal association between tobacco use and COVID-19 during the second wave (1 October 2020-30 June 2021) of the pandemic in Stockholm, Sweden. Methods: A population-based cohort study was conducted in the Stockholm region of Sweden, with information on tobacco use collected prior to the pandemic. Adjusted relative risks (RR) of COVID-19 and 95% confidence intervals (CI) were calculated, contrasting current smokers and snus users to non-users of tobacco. Results: Compared with non-users of tobacco, current smokers had a lower risk of COVID-19 (RR 0.78, 95% CI = 0.75-0.81) and of hospitalisation for the disease. Current snus users had a higher risk of COVID-19. Heavy smokers and snus users had longer hospital stays than non-users of tobacco. Conclusion: Tobacco use may have a different impact on the risk of being infected with SARS-CoV-2 and the risk of developing severe clinical manifestations. Further research is needed to determine the underlying mechanisms.

Current tobacco use and COVID-19 diagnoses in a cohort of adult clients of public dental clinics in Sweden.

Smoking has been linked with both increased and decreased risk of COVID-19, prompting the hypothesis of a protective role of nicotine in the pathogenesis of the disease. Studies of the association between use of smokeless tobacco and COVID-19 would help refining this hypothesis. We analysed data from 424,386 residents in the Stockholm Region, Sweden, with information on smoking and smokeless tobacco (snus) use prior to the pandemic obtained from dental records. Diagnoses of COVID-19 between February and October 2020 were obtained from health-care registers. We estimated the risk of receiving a diagnosis of COVID-19 for current smokers and for current snus users relative to non-users of tobacco, adjusting for potential confounders (aRR). The aRR of COVID -19 was elevated for current snus users (1.09 ;95%CI = 0.99-1.21 among men and 1.15; 95%CI = 1.00-1.33 among women). The risk for women consuming more than 1 can/day was twice as high as among non-users of tobacco. Current smoking was negatively associated with risk of COVID-19 (aRR = 0.68; 95% CI = 0.61-0.75); including hospital admission (aRR = 0.60; 95% CI = 0.47-0.76) and intensive care (aRR = 0.43; 95% CI = 0.21-0.89). The hypothesis of a protective effect of tobacco nicotine on COVID-19 was not supported by the findings. The negative association between smoking and COVID-19 remains unexplained.

Influence of age on the dynamics of fMRI activations during a semantic fluency task.

PURPOSE: Age-related fMRI changes have not been extensively studied for language, whereas important adaptive mechanisms have been seen in other cognitive fields. This study examined age-related changes in fMRI activation during language tasks and, in particular, their dynamic course. PATIENTS AND METHODS: fMRI was performed on 22 young and 21 old healthy right-handed subjects during a silent category word-generation task. Activation and dynamics of BOLD signals were studied separately during the first and second portions of each 30-s block. RESULTS: Activation of the left frontal lobe was initially similar in young and old participants; however, it decreased after 30 s in the old participants. On the other hand, additional areas were initially involved only in old subjects and especially in the default mode network. CONCLUSION: This study showed age-related differences in the dynamics of fMRI activation during a silent word-generation task, suggesting a different pattern of language function with aging.

The InSight HP3 Penetrator (Mole) on Mars: Soil Properties Derived from the Penetration Attempts and Related Activities.

The NASA InSight Lander on Mars includes the Heat Flow and Physical Properties Package HP3 to measure the surface heat flow of the planet. The package uses temperature sensors that would have been brought to the target depth of 3-5 m by a small penetrator, nicknamed the mole. The mole requiring friction on its hull to balance remaining recoil from its hammer mechanism did not penetrate to the targeted depth. Instead, by precessing about a point midway along its hull, it carved a 7 cm deep and 5-6 cm wide pit and reached a depth of initially 31 cm. The root cause of the failure - as was determined through an extensive, almost two years long campaign - was a lack of friction in an unexpectedly thick cohesive duricrust. During the campaign - described in detail in this paper - the mole penetrated further aided by friction applied using the scoop at the end of the robotic Instrument Deployment Arm and by direct support by the latter. The mole tip finally reached a depth of about 37 cm, bringing the mole back-end 1-2 cm below the surface. It reversed its downward motion twice during attempts to provide friction through pressure on the regolith instead of directly with the scoop to the mole hull. The penetration record of the mole was used to infer mechanical soil parameters such as the penetration resistance of the duricrust of 0.3-0.7 MPa and a penetration resistance of a deeper layer ( > 30 cm depth) of 4.9 ± 0.4 MPa . Using the mole's thermal sensors, thermal conductivity and diffusivity were measured. Applying cone penetration theory, the resistance of the duricrust was used to estimate a cohesion of the latter of 2-15 kPa depending on the internal friction angle of the duricrust. Pushing the scoop with its blade into the surface and chopping off a piece of duricrust provided another estimate of the cohesion of 5.8 kPa. The hammerings of the mole were recorded by the seismometer SEIS and the signals were used to derive P-wave and S-wave velocities representative of the topmost tens of cm of the regolith. Together with the density provided by a thermal conductivity and diffusivity measurement using the mole's thermal sensors, the elastic moduli were calculated from the seismic velocities. Using empirical correlations from terrestrial soil studies between the shear modulus and cohesion, the previous cohesion estimates were found to be consistent with the elastic moduli. The combined data were used to derive a model of the regolith that has an about 20 cm thick duricrust underneath a 1 cm thick unconsolidated layer of sand mixed with dust and above another 10 cm of unconsolidated sand. Underneath the latter, a layer more resistant to penetration and possibly containing debris from a small impact crater is inferred. The thermal conductivity increases from 14 mW/m K to 34 mW/m K through the 1 cm sand/dust layer, keeps the latter value in the duricrust and the sand layer underneath and then increases to 64 mW/m K in the sand/gravel layer below. Supplementary Information: The online version contains supplementary material available at 10.1007/s11214-022-00941-z.

Unique structure and optics of the lesser eyes of the box jellyfish Tripedalia cystophora.

The visual system of box jellyfish comprises a total of 24 eyes. These are of four types and each probably has a special function. To investigate this hypothesis the morphology and optics of the lesser eyes, the pit and slit eyes, were examined. The pit eyes hold one cell type only and are probably mere light meters. The slit eyes, comprising four cell types, are complex and highly asymmetric. They also hold a lens-like structure, but its optical power is minute. Optical modeling suggests spatial resolution, but only in one plane. These unique and intriguing traits support strong peripheral filtering.

The initial stage of reversal learning is impaired in mice hemizygous for the vesicular glutamate transporter (VGluT1).

Behavioral flexibility is a complex cognitive function that is necessary for survival in changeable environments. Patients with schizophrenia or Parkinson's disease often suffer from cognitive rigidity, reducing their capacity to function in society. Patients and rodent models with focal lesions in the prefrontal cortex (PFC) show similar rigidity, owing to the loss of PFC regulation of subcortical reward circuits involved in behavioral flexibility. The vesicular glutamate transporter (VGluT1) is preferentially expressed at modulatory synapses, including PFC neurons that project to components of the reward circuit (such as the nucleus accumbens, NAc). VGluT1(+/-) mice display behavioral phenotypes matching many symptoms of schizophrenia, and VGluT1 expression is reduced in the PFC of patients with schizophrenia and Parkinson's disease. Thus, it appears likely that VGluT1-expressing synapses from PFC play a key role in behavioral flexibility. To examine this hypothesis, we studied behavioral flexibility in VGluT1(+/-) mice by testing reversal learning in a visual discrimination task. Here, we show that VGluT1(+/-) mice acquired the initial visual discrimination at the same rate as controls. However, they failed to suppress responses to the previously rewarded stimulus following reversal of reward contingencies. Thus, our genetic disruption of modulatory glutamatergic signaling, including that arising from PFC, appears to have impaired the first stage of reversal learning (extinguishing responses to previously rewarded stimuli). Our data show that this deficit stems from a preservative phenotype. These findings suggest that glutamatergic regulation from the cortex is important for behavioral flexibility and the disruption of this pathway may be relevant in diseases such as schizophrenia.

An econometric analysis of health care expenditure: a cross-section study of the OECD countries.

This paper is an empirical examination of the determinants of aggregate health care expenditure. The paper presents a systematic analysis of relationships across 19 OECD countries, showing the effects of aggregate income, institutional and socio-demographic factors on health care expenditure. The results indicate that institutional factors of the health systems, in addition to per capita Gross Domestic Product (GDP), contribute significantly to the explanation of the health care expenditure variation between countries; for example the way physicians in outpatient care are paid, and the mixture of public/private funding and inpatient/outpatient care.

The whole story: treatment outcomes with Symbicort.

Asthma is a chronic inflammatory disorder of the airways that has a considerable socioeconomic impact. Asthma management guidelines have been introduced to help provide better long-term control of asthma. Although recommended guidelines may increase the direct medication costs, the overall direct costs of asthma may be reduced due to fewer exacerbations. In addition, indirect costs due to lost productivity and mortality are reduced and patients have an improved quality of life. Inhaled corticosteroids are first-line therapy in the treatment of persistent asthma. Against this background, we have assessed the cost-effectiveness of Symbicort (budesonide and formoterol in a single inhaler), a treatment that provides better control of asthma compared with budesonide alone. While the prescribing costs of Symbicort were found to be higher than for budesonide alone, these were partially offset by reduced costs due to fewer asthma exacerbations and a reduced need for other medications. Combined long-term therapy with budesonide and formoterol also improves patient quality of life compared with budesonide alone. Two other factors associated with asthma treatment success and cost-effectiveness are patient/physic an education and good patient adherence to prescribed therapy. The introduction of a single inhaler that is easy to use in simple treatment regimens may improve patient adherence to prescribed medication, thus resulting in improved asthma control and fewer exacerbations. Treatment with Symbicort is more cost-effective than treatment with budesonide alone.

The costs of exacerbations in chronic obstructive pulmonary disease (COPD).

Exacerbations are the key drivers in the costs of chronic obstructive pulmonary disease (COPD). The objective was to examine the costs of COPD exacerbations in relation to differing degrees of severity of exacerbations and of COPD. We identified 202 subjects with COPD, defined according to the BTS and ERS criteria. Exacerbations were divided into mild (self-managed), mild/moderate (telephone contact with a health-care centre and/or the use of antibiotics/systemic corticosteroids), moderate (health-care centre visits) and severe (emergency care visit or hospital admission). Exacerbations were identified by sending the subjects a letter inquiring whether they had any additional respiratory problems or influenza the previous winter. At least one exacerbation was reported by 61 subjects, who were then interviewed about resource use for these events. The average health-care costs per exacerbation were SEK 120 (95% C=39-246), SEK 354 (252-475), SEK 2111 (1673-2612) and SEK 21852 (14436-29825) for mild, mild/moderate, moderate and severe exacerbations, respectively. Subjects with impaired lung function experienced more severe exacerbations, which was also reflected in the cost of exacerbations per severity of the disease during the 4 1/2 month study period (ranging from SEK 224 for mild to SEK 13708 for severe cases, median SEK 940). Exacerbations account for 35-45% of the total per capita health-care costs for COPD. In conclusion, costs varied considerably with the severity of the exacerbation as well as with the severity of COPD. The prevention of moderate-to-severe exacerbations could be very cost-effective and improve the quality of life.

Adding formoterol to budesonide in moderate asthma--health economic results from the FACET study.

The FACET (Formoterol and Corticosteroid Establishing Therapy) study established that there is a clear clinical benefit in adding formoterol to budesonide therapy in patients who have persistent symptoms of asthma despite treatment with low to moderate doses of an inhaled corticosteroid. We combined the clinical results from the FACET study with an expert survey on average resource use in connection with mild and severe asthma exacerbations in the U.K., Sweden and Spain. The primary objective of this study was to assess the health economics of adding the inhaled long-acting beta2-agonist formoterol to the inhaled corticosteroid budesonide in the treatment of asthma. The extra costs of adding the inhaled beta2-agonist formoterol to the corticosteroid budesonide in asthmatic patients in Sweden were offset by savings from reduced use of resources for exacerbations. For Spain the picture was mixed. Adding formoterol to low dose budesonide generated savings, whereas for moderate doses of budesonide about 75% of the extra formoterol costs could be recouped. In the U.K., other savings offset about half of the extra cost of formoterol. All cost-effectiveness ratios are within accepted cost-effectiveness ranges reported from previous studies. If productivity losses were included, there were net savings in all three countries, ranging from Euro 267-1183 per patient per year. In conclusion, adding the inhaled, long-acting beta2-agonist formoterol to low-moderate doses of the inhaled corticosteroid budesonide generated significant gains in all outcome measures with partial or complete offset of costs. Adding formoterol to budesonide can thus be considered to be cost-effective.

Methodological aspects of international drug price comparisons.

Drug prices have become an important issue in the last few years as concerns about constrained healthcare resources have increased. Healthcare authorities in all industrialised countries are questioning whether their country is carrying a heavier burden than others in paying for drugs. In view of this discussion, several price comparison studies have been conducted. However, there is no generally accepted methodology on how to conduct price comparisons, and many methodological issues remain unresolved. The results of most published studies are affected by moderately serious methodological flaws, which are never properly addressed. The purpose of this study is to discuss the methodological issue of international drug price comparison, in terms of 6 points that appear to this author to be necessary to conduct a methodologically sound study. A previous review of a large number of drug price comparisons revealed that they all fail to take into account some or all of these 6 basic methodological points. Studies that fulfil the methodological criteria outlined in this paper are therefore urgently needed before drug pricing studies can be fully utilised as a basis for important policy decisions in the healthcare arena.

The cost of angina pectoris in Sweden.

A survey of 402 Swedish patients with angina pectoris was performed to estimate the annual direct medical costs, and nonmedical costs, of a typical Swedish angina pectoris patient, and to identify those variables having the greatest impact on the direct medical costs. Data regarding the consumption of healthcare services over a 3-month period were collected through telephone interviews conducted by trained nurses at a medical marketing agency. The data were multiplied by 4 to obtain an estimate of the annual resource consumption. The annual direct medical cost of angina pectoris was estimated at 40,052 Swedish krona (SEK; $US1 approximately SEK7.20, March 1995) per patient, comparable with the cost of a myocardial infarction. As expected, however, the severity of angina pectoris was important in determining the direct medical cost. The significant variables explaining variations in direct costs were (in order of importance): (i) whether the patient had undergone cardiovascular surgery; (ii) whether the patient was treated by a general practitioner or an internist; (iii) the number of years since first diagnosis of angina pectoris; and (iv) whether the patient's angina pectoris was characterised as stable or unstable. The annual nonmedical cost of angina pectoris per patient was estimated at SEK38,225. The relatively high costs of angina pectoris underline the importance of health economic evaluations of various diseases and medical interventions.

The costs and benefits of switching a drug from prescription-only to over-the-counter status: a review of methodological issues and current evidence.

In recent years various governments, pharmacy associations, consumer groups and the pharmaceutical industry have suggested that more drugs should be switched from prescription-only (Rx) to over-the-counter (OTC) status. Many rationales have been offered, including lowering healthcare costs, taking advantage of pharmacists' training and knowledge, promoting the concept of prevention and self-care, and increasing sales of pharmaceuticals. The purpose of this article is to examine the current state of knowledge on assessing the effects of such a change. First, the paper discusses the methodology and data necessary for conducting an assessment of the costs and benefits of switching a drug from Rx to OTC status. Basically two methods, the economic theory of consumers' surplus and the epidemiological approach, are available; the choice of method depends on the drug examined and the data available. Secondly, the article discusses existing evidence pertaining to the costs and benefits of these switches. Based on our review of the literature, we conclude that the benefits, to individual consumers and to society as a whole, resulting from a change in prescription status outweigh the costs. The extent of the benefits depends on the type of drug and the size of the market.

Cost effectiveness in the treatment of heart failure with ramipril. A Swedish substudy of the AIRE study. Acute Infarction Ramipril Efficacy.

We estimated the cost effectiveness of adding the ACE inhibitor ramipril to conventional treatment in patients with heart failure after acute myocardial infarction. These estimates were based on the Acute Infarction Ramipril Efficacy (AIRE) study and on complementary Swedish healthcare resource use data for a subset of patients. The average follow-up period was 15 months (minimum 6 months, maximum 3.8 years). The perspective of the analysis was that of the county councils (third-party payers), and we focused on the cost of drugs and hospitalisation. The marginal cost effectiveness of the treatment was estimated over 3 treatment periods: 1, 2 and 3.8 years. The cost-effectiveness ratios varied between SEK14,148 and SEK33,033 per life-year gained ($US1 = SEK7.70. Pounds 1 = SEK12.40) for the 3 treatment periods. Adding ramipril to conventional treatment for heart failure after acute myocardial infarction is therefore cost effective, and compares favourably with the cost effectiveness of other common medical therapies in the cardiovascular field.

Angiotensin converting enzyme (ACE) inhibitors and heart failure. The consequences of underprescribing.

Heart failure (HF) is a common and expensive cardiovascular disease, in economic terms as well as in lives lost. Angiotensin converting enzyme (ACE) inhibitors have been shown to significantly reduce mortality and hospitalisation in HF. However, recent surveys show that the prescription rate of ACE inhibitors for HF is far below what is considered to be optimal. Furthermore, prescribed dosages are usually lower than those recommended based on evidence from clinical trials. This article estimates the consequences, both economic and human, of underprescribing ACE inhibitors in patients with HF. The indication for prescribing an ACE inhibitor varies, and clinical trials have included different categories of patients; it is inappropriate to assess costs in all eligible patients without taking these factors into account. Therefore, we analysed the data with respect to 4 different groups: (i) asymptomatic left ventricular systolic dysfunction (LVSD)--an early stage leading to chronic HF; (ii) chronic HF; and post-myocardial infarction (MI) LVSD differentiated into (iii) post-MI asymptomatic LVSD and (iv) post-MI chronic HF. We also estimated the cost effectiveness of adding an ACE inhibitor to the treatment of patients with HF for whom an ACE inhibitor is not currently prescribed. If only patient populations in which large trials have shown a significant effect of ACE inhibition on mortality are included in the analysis (i.e. excluding asymptomatic patients with LVSD), increasing the number of Swedish patients receiving an ACE inhibitor could save in excess of 3700 lives each year, in addition to reducing the annual number of hospitalisations by 8400. The additional cost would be 101.5 million Swedish kronor (SEK), a cost per life saved of SEK27 200. Chronic HF is the most cost-effective patient population to treat, generating cost savings under certain assumptions. A further 6700 hospitalisations can be avoided should the use of ACE inhibitors be extended to asymptomatic patients with LVSD. Increasing dosages to those used in the large clinical trials may generate additional savings in lives and hospitalisations. In conclusion, the use of ACE inhibitors in HF and LVSD has clearly been proven to be cost effective, and compares favourably with the cost effectiveness of treating hypertension or hypercholesterolaemia. At present, however, ACE inhibitors are not optimally utilised. Given the increasingly constrained resources for healthcare, every effort should be made to increase the use of cost-effective treatments, such as ACE inhibitors in chronic HF and post-MI LVSD.

Cost effectiveness of antiviral treatment with zalcitabine plus zidovudine for AIDS patients with CD4+ counts less than 300/microliters in 5 European countries.

A cost-effectiveness model was developed on the basis of early clinical trial results from the US reporting sustained CD4+ cell response in patients receiving zalcitabine in addition to zidovudine. This model was then adapted and applied to 5 European countries to assess the comparative cost effectiveness of adding zalcitabine to antiviral treatment for AIDS patients. The countries included in the modelling effort were Switzerland, France, Italy, Germany and the UK. The model used a Markov state-transition process to estimate the rate of acute opportunistic disease episodes, lifetime medical treatment costs, and survival for populations of AIDS patients with baseline CD4+ counts of less than 300/microliters. Physician panels in each country developed standard treatment algorithms and adjusted the epidemiological data to reflect the AIDS profile of each country. Economic consultants provided cost data. Results from this exploratory data analysis show that if CD4+ counts correlate with the incidence of opportunistic disease episodes as expected, the combined use of zalcitabine and zidovudine for a 1-year period should be cost effective.