Revealing causal heterogeneity using time series analysis of ambulatory assessments: application to the association between depression and physical activity after myocardial infarction

Objective: Studies in psychosomatic medicine are characterized by analyses that typically compare groups. This nomothetic approach leads to conclusions that apply to the average group member but not necessarily to individual patients. Idiographic studies start at the individual patient and are suitable to study associations that differ between time points or between individuals. We illustrate the advantages of the idiographic approach in analyzing ambulatory assessments, taking the association between depression and physical activity after myocardial infarction as an example. Methods: Five middle-aged men who had myocardial infarction with mild to moderate symptoms of depression were included in this study. Four of these. participants monitored their physical activity and depressive symptoms during a period of 2 to 3 months using a daily self-registration form. The time series of each individual participant were investigated using vector autoregressive modeling, which enables the analysis of temporal dynamics between physical activity and depression. Results: We found causal heterogeneity in the association between depression and physical activity. Participants differed in the predominant direction of effect, which was either from physical activity to depression (n = 1,85 observations, unstandardized effect size = -0.183, p=.03) or from depression to physical activity (n = 2, 65 and 59 observations, unstandardized effect sizes = -0.038 and -0.381, p<.001 and p=.04). Also, the persistency of effects differed among individuals. Conclusions: Vector autoregressive models are suitable in revealing causal heterogeneity and can be easily used to analyze ambulatory assessments. We suggest that these models might bridge the gap between science and clinical practice by translating epidemiological results to individual patients

Sex dependent risk factors for mortality after myocardial infarction : individual patient data meta-analysis

Background. Although a number of risk factors are known to predict mortality within the first years after myocardial infarction, little is known about interactions between risk factors, whereas these could contribute to accurate differentiation of patients with higher and lower risk for mortality. This study explored the effect of interactions of risk factors on all-cause mortality in patients with myocardial infarction based on individual patient data meta-analysis. Methods. Prospective data for 10,512 patients hospitalized for myocardial infarction were derived from 16 observational studies (MINDMAPS). Baseline measures included a broad set of risk factors for mortality such as age, sex, heart failure, diabetes, depression, and smoking. All two-way and three-way interactions of these risk factors were included in Lasso regression analyses to predict time-to-event related all-cause mortality. The effect of selected interactions was investigated with multilevel Cox regression models. Results. Lasso regression selected five two-way interactions, of which four included sex. The addition of these interactions to multilevel Cox models suggested differential risk patterns for males and females. Younger women (ag

Forensic microbiology reveals that Neisseria animaloris infections in harbour porpoises follow traumatic injuries by grey seals

Neisseria animaloris is considered to be a commensal of the canine and feline oral cavities. It is able to cause systemic infections in animals as well as humans, usually after a biting trauma has occurred. We recovered N. animaloris from chronically inflamed bite wounds on pectoral fins and tailstocks, from lungs and other internal organs of eight harbour porpoises. Gross and histopathological evidence suggest that fatal disseminated N. animaloris infections had occurred due to traumatic injury from grey seals. We therefore conclude that these porpoises survived a grey seal predatory attack, with the bite lesions representing the subsequent portal of entry for bacteria to infect the animals causing abscesses in multiple tissues, and eventually death. We demonstrate that forensic microbiology provides a useful tool for linking a perpetrator to its victim. Moreover, N. animaloris should be added to the list of potential zoonotic bacteria following interactions with seals, as the finding of systemic transfer to the lungs and other tissues of the harbour porpoises may suggest a potential to do likewise in humans

Myocardial infarction and generalised anxiety disorder: 10-year follow-up

BACKGROUND: Few studies have addressed the relationship between generalised anxiety disorder and cardiovascular prognosis using a diagnostic interview. AIMS: To assess the association between generalised anxiety disorder and adverse outcomes in patients with myocardial infarction. METHOD: Patients with acute myocardial infarction (n = 438) were recruited between 1997 and 2000 and were followed up until 2007. Current generalised anxiety disorder and post-myocardial infarction depression were assessed with the Composite International Diagnostic Interview. The end-point consisted of all-cause mortality and cardiovascular-related readmissions. RESULTS: During the follow-up period, 198 patients had an adverse event. Generalised anxiety disorder was associated with an increased rate of adverse events after adjustment for age and gender (hazard ratio: 1.94; 95% confidence interval: 1.14-3.30; P = 0.01). Additional adjustment for measures of cardiac disease severity and depression did not change the results. CONCLUSIONS: Generalised anxiety disorder was associated with an almost twofold increased risk of adverse outcomes independent demographic and clinical variables and depression

Prognostic association of anxiety post myocardial infarction with mortality and new cardiac events: a meta-analysis

Objective: To assess the association of anxiety after myocardial infarction (MI) with cardiac prognosis. Methods: A meta-analysis of references derived from MEDLINE, EMBASE, and PSYCINFO (1975-March 2009) was performed without language restrictions. End point was cardiac outcome defined as all-cause mortality, cardiac mortality, and cardiac events. The authors selected prospective studies with at least 6 months follow-up, and anxiety had to be assessed within 3 months after MI with reliable and valid instruments. Results: Twelve papers met selection criteria. These studies described follow-up (on average, 2.6 years) of 5750 patients with MI. Anxious patients were at risk of adverse events (odds ratio (OR) fixed, 1.36; 95% confidence interval (CI), 1.18-1.56; p < .001). Anxiety was also specifically associated with all-cause mortality (OR fixed, 1.47; 95% CI, 1.02-2.13; p = .04), cardiac mortality (OR fixed, 1.23; 95% CI, 1.03-1.47; p = .02), and new cardiac events (OR fixed, 1.71; 95% CI, 1.31-2.23; p < .001). Conclusions: Post-MI anxiety is associated with a 36% increased risk of adverse cardiac outcomes in bivariate analyses. Because the existing literature is small and contains several limitations, more research is needed to evaluate the association of anxiety and prognosis in patients with MI and to assess the extent to which this association is independent of clinical variables, such as disease severity, and other psychological variables, especially depression