Stability of older adults' preferences for life-sustaining medical treatment.

The use of instructional advance directives assumes that preferences for life-sustaining medical treatment remain stable over time and across changes in life condition. A sample of 332 older adults recorded their preferences for 4 life-sustaining treatments in 9 illness scenarios. These preferences were elicited again 1 and 2 years after the original interview. Overall, preferences for life-sustaining treatment were moderately stable over time, but stability varied significantly across judgments. Preferences were most stable for illness scenarios that were most and least serious and for decisions to refuse treatment. Age, gender, education, and prior completion of an advance directive were all related to preference stability, and evidence indicated that declines in physical or psychological functioning resulted in decreased interest in life-sustaining treatment.     

Accuracy of Clinician Predictions of Future Self‐Harm: A Systematic Review and Meta‐Analysis of Predictive Studies

Assessment of a patient after hospital‐treated self‐harm or psychiatric hospitalization often includes a risk assessment, resulting in a classification of high risk versus low risk for a future episode of self‐harm. Through systematic review and a series of meta‐analyses looking at unassisted clinician risk classification (eight studies; N = 22,499), we found pooled estimates for sensitivity 0.31 (95% CI: 0.18–0.50), specificity 0.85 (0.75–0.92), positive predictive value 0.22 (0.21–0.23), and negative predictive value 0.89 (0.86–0.92). Clinician classification was too inaccurate to be clinically useful. After‐care should therefore be allocated on the basis of a needs rather than risk assessment.     

In Honor of My Father and My Son

The author advises survivors on the four tasks of grief and reflects on the suicide of her college-age son in 1977 and the recent death of her father, a suicidologist, from age-related causes. She describes current collaborative efforts by organizations dedicated to the prevention and aftermath of suicide.     

Interaction of Combat Exposure and Unit Cohesion in Predicting Suicide‐Related Ideation Among Post‐Deployment Soldiers

Suicide is one of the leading causes of death among U.S. Army soldiers. Suicide‐related ideation, which is associated with suicide attempts and suicide, can cause considerable distress. In a sample of 1,663 recently redeployed soldiers, we used factor analysis and structural equation modeling to test the associations between combat exposure, unit cohesion, and their interaction in predicting suicide‐related ideation. We found that combat exposure was a significant risk factor for suicide‐related ideation, while unit cohesion was a significant protective factor. The significant interaction between the two factors indicated that soldiers who experienced greater combat exposure but also had higher levels of unit cohesion had relatively lower levels of suicide‐related ideation. In addition, those who had higher levels of combat exposure and lower unit cohesion were most at risk for suicide‐related ideation. Our findings indicate the importance of unit cohesion in protecting soldiers from suicide‐related ideation and suggest a higher risk group of soldiers who should be targeted for interventions.     

Response-time dynamics: Evidence for linear and low-dimensional nonlinear structure in human choice sequences

Response time (RT) is a commonly used measure of cognitive performance, which is usually characterized as stochastic. However, useful information may be hidden in the apparently random fluctuations of RT. Dynamical systems analysis techniques allow an exploration of the alternative hypothesis that RT fluctuations are deterministic, albeit in a complex manner. We applied careful task construction and noise-reduction and surrogate series tests to show that RT series from a forced-pace serial response-time task have low-dimensional chaotic characteristics. In Experiment 1, 80% of subjects' filtered RT series had low dimensionality, sensitive dependence on initial conditions, spectra close to 1/ f , and stable attractor geometry across sessions. In Experiment 2, we showed that the size of the inter-stimulus interval (ISI) determined the number of subjects with low-dimensional chaotic series. A small ISI caused 100% of subjects to respond in the chaotic regime, whereas only 25% had a low-dimensional chaotic RT component when the ISI was large. We argue that demanding task requirements cause a reduction in the dimensionality of the dynamics, producing RT fluctuations that may reflect a response strategy for controlling RT.