Mark D. Pagel

Social networks: we get by with (and in spite of) a little help from our friends.

Studies of social support networks have almost exclusively measured only their positive aspects. In this research, we investigated both the helpful or positive and the upsetting or negative aspects of social networks in a longitudinal study of spouses caring for a husband or wife with Alzheimers disease, a progressive senile dementia. Measures of helpful and upsetting aspects of the care givers networks, derived from interviews and daily interaction ratings, were studied for their relations with overall network satisfaction and depression at an initial interview period (n = 68) and at a follow-up period about 10 months later (n = 38). Results from hierarchical multiple regression analyses, in which care givers age and sex and a measure of the spouses health status were controlled, showed that the care givers degree of upset with their networks was strongly associated with lower network satisfaction and increased depression at both time periods. Helpful aspects bore little or no direct relation to either depression or network satisfaction. Helpful aspects of the network did, however, interact with network upset in predicting network satisfaction, and depression (combined probabilities test, p less than .05). Longitudinal predictions of follow-up depression, after age, sex, care givers health status, and initial depression levels were controlled, showed that changes in upsetting aspects of ones network were predictive of changes in depression over time. We interpreted these results within an attributional framework that emphasizes the salience of upsetting events within a social network.

Psychosocial influences on new born outcomes: A controlled prospective study

This paper reports the results of a prospective investigation of 100 women during their pregnancies to test the hypothesis that social and psychological factors influence pregnancy outcome after controlling for demographic, biomedical, and lifestyle variables. Subjects completed questionnaires that assessed family social supports, life events, and anxiety. In addition, data were collected on general biomedical and pregnancy risk, lifestyle practices including smoking and drinking, as well as demographic information. Four infant outcomes, birthweight, gestational age, and 1 and 5 min Apgar scores, were studied via hierarchical multiple regression analyses for their relationship to the social and psychological variables, after controlling for all other sets of variables. The results of these analyses showed that life events stress accounted for significant variation in birthweight, and social supports and anxiety were associated with the two pediatric Apgar scores. Gestational age bore a simple relationship to anxiety, with higher anxiety predictive of lower gestational age. Further analyses revealed that women with either low social supports or high anxiety were, on the average, younger, more often single, of lower education level, had less income, smoked more, and had higher general biomedical risk than women with adequate social supports or lower anxiety. This suggests the multiple ways in which social and psychological risk factors may be related to pregnancy outcome and emphasizes the need for well controlled studies in this area.

A comparison of three social-psychological models of attitude and behavioral plan: prediction of contraceptive behavior.

We compared the predictive validities of three prominent models of attitudes and behavioral decisions: Rosenbergs instrumentality-value model, Fishbeins belief-evaluation model, and Beachs adaptation of subjective expected utility theory. Seventy female undergraduates rated each of the models components and reported their attitudes and behavioral plans toward using three different methods of contraception. With the traditional across-subjects prediction procedure, the Rosenberg model generally accounted for 5-25% less variance in subjects attitudes and behavioral plans than the Fishbein an Beach models, which were not different. With a within-subject prediction procedure, the Rosenberg model was again the least accurate, and the Fishbein and Beach models had similar predictive accuracy. As hypothesized, within-subject predictions were more accurate than across-subjects predictions. The relatively poor performance of the Rosenberg model was attributable to the instrumentality component. In addition, we found that the Beach model could be simplified with no appreciable loss in predictive accuracy. Finally, a subjects personal normative beliefs emerged as a strong independent predictor of behavioral plan.

Predicting who will benefit from behavioral marital therapy.

On a tente de discerner le role des preferences daffiliation/independance dans la prediction de lefficacite dune therapie de couple. On a utilise une technique de traitement des donnees permettant de predire les changements dans la satisfaction conjugale, 1) immediatement apres traitement; 2) et apres un suivi de six mois

Prediction of pregnancy complications: An application of the biopsychosocial model

This paper describes a pilot study of biomedical and psychosocial risk and the outcome of pregnancy. Ninety-three pregnant women completed four instruments to identify three types of psychosocial risk: life events, family function and social support. Biomedical risk was identified through analysis of self-reported health histories and hospital records. Information on complications of pregnancy was obtained from hospital delivery records. Further complications data were obtained by a home interview at 6 weeks postpartum. In the sample studied, from an agricultural-university community in Eastern Washington, biomedical risk alone was not substantially related to complications. Psychosocial risk was related to both delivery and postpartum complications. Family function was the best single psychosocial predictor. The interaction between family function and biomedical risk also predicted complications reliability. A total of 11% of variance in postpartum complications could be explained jointly by biomedical and psychosocial risk. The results of the study suggest that psychosocial risk assessment alone and in interaction with biomedical risk assessment will offer significant improvement in the identification of women who may experience pregnancy complication.

Depressive thinking and depression: relations with personality and social resources.

The mechanisms by which social supports and personality variables may buffer against psychopathology are not well understood. We studied depression, depressive cognitions, social supports, and self-esteem in a sample of 68 spouse-caregivers of patients with Alzheimers Disease in an attempt to identify possible buffering mechanisms of the latter two variables. Specifically, we hypothesized that the well-known relation of depressive cognitions to depression would vary as a function of satisfaction with social supports and with level of self-esteem. Hierarchical multiple regression analyses conducted to predict depression revealed significant and independent main effects for depressive cognitions (p less than .01), social supports (p less than .025), and self-esteem (p less than .001), with depressive cognitions associated with higher depression and the other two variables associated with reduced depression (R2 = .53 for the three main effects). In addition, the relation of depressive cognitions with depression varied substantially depending on the level of social supports (p less than .01); caregivers with high levels of depressive cognitions had high levels of depression only if social supports were low (R2 = .61 including interaction). Self-esteem and depressive cognitions showed a similar interaction, but it failed to reach significance. Analyses to determine whether self-esteem and social supports were directly associated with lower depressive cognitive activity yielded a main effect for self-esteem only (p less than .03). Thus, whereas social supports and self-esteem were directly associated with lower depression, only the social supports variable was further associated with reduced depression because it apparently buffered the impact of depressive thinking. Self-esteem was also indirectly associated with lower depression via its relation with lower depressive thinking. Implications of our results for cognitive theories of depression and for the psychosocial mechanisms of stress buffering are discussed.

Comment on hoerl and kennard's ridge regression simulation methodology

Ridge regression has received strong support in several Monte carlo studies, leading some authors to advocate its general use. It is argued, however, that these studies were strongly biased in favor of ridge regression by simulating regression coefficient vectors centered at the origin; a condition well suited for a shrinkage technique. Studies which modeled some non-zero regression coefficients and which showed only qualified support for ridge regression are cited in support of this argument. It is concluded that only to the extent that ridge regression type coefficient vectors actually underlie real data sets -a poorly understood phenomenon - will ridge regression be of use.

Effects of oxygen administration on the manifestation of acetate intolerance in dialysis patients

In a prospective double-blind study. 12 patients were dialyzed four times each with nasal oxygen (O2) and 4 times each with air throughout acetate dialysis. Fewer symptoms (p less than 0.01), improved postdialysis task performance (p less than 0.04) and a tendency for less mean blood pressure drop (p less than 0.07 two-sided) were noted on O2 dialyses than on air dialyses. The rate of acetate metabolism was increased during O2 dialyses since serum acetate levels were significantly lower at 2, 3 and 4 h. Significant hypoxemia was demonstrated in 10 of these patients on acetate dialysis without O2. These results clearly demonstrate that: (1) prevention Of hypoxemia during dialysis reduces acetate intolerance, and (2) compromised tissue O2 availability may be partly responsible for dialysis morbidity.