Background

Dual processing theory of human cognition postulates that reasoning and decision-making can be described as a function of both an intuitive, experiential, affective system (system I) and/or an analytical, deliberative (system II) processing system. To date no formal descriptive model of medical decision-making based on dual processing theory has been developed. Here we postulate such a model and apply it to a common clinical situation: whether treatment should be administered to the patient who may or may not have a disease.

Methods

We developed a mathematical model in which we linked a recently proposed descriptive psychological model of cognition with the threshold model of medical decision-making and show how this approach can be used to better understand decision-making at the bedside and explain the widespread variation in treatments observed in clinical practice.

Results

We show that physician’s beliefs about whether to treat at higher (lower) probability levels compared to the prescriptive therapeutic thresholds obtained via system II processing is moderated by system I and the ratio of benefit and harms as evaluated by both system I and II. Under some conditions, the system I decision maker’s threshold may dramatically drop below the expected utility threshold derived by system II. This can explain the overtreatment often seen in the contemporary practice. The opposite can also occur as in the situations where empirical evidence is considered unreliable, or when cognitive processes of decision-makers are biased through recent experience: the threshold will increase relative to the normative threshold value derived via system II using expected utility threshold. This inclination for the higher diagnostic certainty may, in turn, explain undertreatment that is also documented in the current medical practice.

Conclusions

We have developed the first dual processing model of medical decision-making that has potential to enrich the current medical decision-making field, which is still to the large extent dominated by expected utility theory. The model also provides a platform for reconciling two groups of competing dual processing theories (parallel competitive with default-interventionalist theories).

Aim: Genome-wide association studies have identified variants on chromosome 9p21 that are associated with coronary heart disease (CHD). The relationship between these variants and the age of onset of CHD is less clear. The aim of this study was to examine the allelic frequencies and haplotype structure of eight single-nucleotide polymorphisms (SNPs) on chromosome 9p21 in ethnically diverse women. We also explored the relationship between 9p21 SNPs and the age of CHD onset. Results: There was considerable interethnic allelic and haplotype diversity across the 9p21 locus with only two SNPs (rs10757274 and rs4977574) in perfect linkage disequilibrium in both races, and only a small proportion of the haplotypes shared between the racial groups. With the exception of rs1333040, whites with at least one copy of the 9p21 SNP risk alleles were found to have CHD from 1.45 (rs10116277) to 4.77 (rs2383206) years earlier than those with the wild-type alleles. Blacks carrying at least one copy of the risk allele (92%) for rs1333040 had a CHD age of onset that was 6.5 years earlier than those with the wild-type alleles. Conclusions: Different variants on chromosome 9p21 may influence CHD age of onset in whites and blacks.

Objective

This study analyzed relationship between prenatal mood states and serological evidence of immune response to Toxoplasma gondii (T.gondii). A secondary aim was to determine if thyroid peroxidase (TPO) autoantibody status was related to T.gondii status.

Study Design

Pregnant women (N=414) were measured between 16 to 25 weeks gestation with demographic and mood questionnaires and a blood draw. All plasma samples were analyzed for TPO and T. gondii IgG, tryptophan, kynurenine and neopterin. Cytokines were available on a subset (N=142).

Results

Women with serological evidence of exposure to T. gondii (N=44) showed positive correlations between IgG levels, and the Profile of Mood Scales (POMS) depression and anxiety subscales. Plasma TNF-α was higher in T. gondii positive women.

Conclusions

Higher T. gondii IgG titers in infected women were related to anxiety and depression during pregnancy. Reactivation of T.gondii or immune responses to T.gondii may alter mood in pregnant women.

PURPOSE

The aim of this study was to compare the effects of a cardiac rehabilitation (CR) program tailored for women to a traditional program on perceptions of health among women with coronary heart disease.

METHODS

This 2-group randomized clinical trial compared the perceptions of health among 92 women completing a traditional 12-week CR program to 133 women completing a tailored program that included motivational interviewing guided by the Transtheoretical model of behavior change. Perceptions of health were measured using the SF-36 health survey at baseline, post-intervention, and at 6-month follow-up. ANOVA was used to compare changes in SF-36 subscale scores over time.

RESULTS

The group by time interaction was significant for the general health (F(2,446) = 3.80, P=.023), social functioning (F(2,446) = 4.85, P=.008), vitality (F(2,446) = 5.85, P=.003), and mental health (F(2,446) = 3.61, P=.028), subscales indicating that the pattern of change was different between the 2 groups. Of the 4 subscales on which there were significant group by time interactions, the tailored group demonstrated improved scores over time on all 4 while the traditional group improved on only the emotional role limitations and vitality subscales.

CONCLUSIONS

A tailored CR program improved general health perceptions, mental health, vitality, and social functioning in women when compared to traditional CR. To the extent that perceptions of health contribute to healthy behaviors fostered in CR programs, tailoring CR programs to alter perceptions of health may improve adherence.

Abstract

Background

Women with heart disease have adverse psychosocial profiles and poor attendance in cardiac rehabilitation (CR) programs. Few studies examine CR programs tailored for women for improving their quality of life (QOL).

Methods

This randomized clinical trial (RCT) compared QOL among women in a traditional CR program with that of women completing a tailored program that included motivational interviewing guided by the Transtheoretical Model (TTM) of behavior change. Two measures of QOL, the Multiple Discrepancies Theory questionnaire (MDT) and the Self-Anchoring Striving Scale (SASS), were administered to 225 women at baseline, postintervention, and 6-month follow-up. Analysis of Variance (ANOVA) was used to compare changes in QOL scores over time.

Results

Baseline MDT and SASS scores were 35.1 and 35.5 and 7.1 and 7.0 for the tailored and traditional CR groups, respectively. Postintervention, MDT and SASS scores increased to 37.9 and 7.9, respectively, for the tailored group compared with 35.9 and 7.1 for the traditional group. Follow-up scores were 37.7 and 7.6 for the tailored group and 35.7 and 7.1 for the traditional group. Significant group by time interactions were found. Subsequent tests revealed that MDT and SASS scores for the traditional group did not differ over time. The tailored group showed significantly increased MDT and SASS scores from baseline to posttest, and despite slight attenuation from posttest to 6-month follow-up, MDT and SASS scores remained higher than baseline.

Conclusions

The CR program tailored for women significantly improved global QOL compared with traditional CR. Future studies should explore the mechanisms by which such programs affect QOL.

Background

Metabolic syndrome (MetS) and elevated inflammatory markers, both predictors of future cardiovascular events, are more prevalent in women with coronary heart disease (CHD). The influence of cardiac rehabilitation (CR) on MetS and inflammatory biomarkers is not well characterized for women.

Purpose

The purpose of this paper is to examine the effects of a 12-week behaviorally enhanced CR exclusively for women compared to traditional CR on components of the MetS and inflammatory markers in women with CHD.

Methods

The randomized clinical trial employed 2 treatment groups; both receiving a comprehensive 12-week CR program, with 1 group receiving a motivationally enhanced intervention exclusively for women. A subset of 91 women (mean age 61.6 years) from the parent study provided serum samples to examine the effects of CR on high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and intercellular adhesion molecule-1 (ICAM-1).

Results

Following CR, the total sample of women demonstrated significant reductions in hsCRP (P=.002), IL-6 (P<.001), TNF-α (P=.010), and ICAM-1 (P=.016). Women in the gender-tailored CR program, significantly improved all biomarker levels compared to baseline (P<.05 for all) while those in the traditional group improved only hsCRP (P=<.05) and IL-6 (P<.05) levels. The combined study group demonstrated improvements in several components of the MetS (triglycerides, waist circumference, and systolic blood pressure) but not others (high-density lipoprotein cholesterol, fasting glucose, and diastolic blood pressure).

Conclusion

Cardiac rehabilitation promotes greater improvements in inflammatory biomarkers than in components of MetS for women with CHD. Improvements in body composition or weight may not be a precondition for the benefits of exercise due to loss of abdominal fat. Examining components of MetS as continuous variables is recommended to prevent lost information inherent in dichotomization.