Longitudinal effects of integrated treatment on alcohol use for persons with serious mental illness and substance use disorders.

A randomized experimental design was used to assign participants to an integrated mental health and substance use treatment program or to standard hospital treatment. A multilevel, nonlinear model was used to estimate hospital treatment effects on days of alcohol use for persons with serious mental illness and substance use disorders over 18 months. The integrated treatment program had a significant effect on the rate of alcohol use at 2 months postdischarge, reducing the rate of use by 54%. Motivation for sobriety at hospital discharge, posttreatment self-help attendance, and social support for sobriety were also found to reduce the rate of use during the follow-up period. Implications for mental health treatment and aftercare support are discussed.

The effects of sponsorship on PPO performance.

In trying to build a "better health care mousetrap," hospitals, physicians, insurers, employers and other are sponsoring PPOs. Two Mercer-Meidinger-Hansen consultants who specialize in evaluating managed care plans discuss what prompts various sponsors to establish a PPO and how purchasers can discern the effects of these motivations on the plan's objectives, operational components and outcomes.

Enhancing utilization review program results.

Utilization review programs are increasing in number and type, but their true contributions to payers' health care and cost management efforts vary tremendously, according to evaluations of over 100 private UR firms by National Medical Audit. Three senior executives of that firm discuss state-of-the-art criteria and methods for gauging the effectiveness of a UR program.

Natural concepts in pigeons.

Pigeons learned to discriminate pictures of trees, bodies of water, or a particular person in three separate experiments. Pictures being seen for the first time were discriminated almost as well as pictures seen in training. The pigeons in each experiment showed similar patterns of errors and correct discrimination.

Matching in a network.

Pigeons were given practice choosing between pairs of alternatives yielding different frequencies of reinforcement. Four individual alternatives were set into four pairwise choices. Averaged over subjects, the distribution of responses in each choice approximated matching. The four individual alternatives were then presented, two by two, in two pairwise choices for which there had been no initial practice. No further reinforcement was given during the tests with the new pairs. Transfer to the two test pairs deviated systematically from matching in most cases by exaggerating the preference for the alternative that had had the higher frequency of reinforcement.

Maximizing and matching on concurrent ratio schedules.

Pigeons on concurrent variable-ratio variable-ratio schedules usually, though not always, maximize reinforcements per response. When the ratios are equal, maximization implies no particular distribution of responses to the two alternatives. When the ratios are unequal, maximization calls for exclusive preference for the smaller ratio. Responding conformed to these requirements for maximizing, which are further shown to be consistent with the conception of reinforcement implicit in the matching law governing relative responding in concurrent interval schedules.

Hunger and contrast in a multiple schedule.

Pigeons working for food on a multiple variable-interval 1-min-variable-interval 4-min schedule were subjected to variations in body weight, presumably causing changes in hunger. The proportion of responses in each component approached and eventually reached the proportion of reinforcements as body weight increased. This effect follows from the matching-law interpretation of contrast in multiple schedules.

Food-avoidance in hungry pigeons, and other perplexities.

Twenty-three pigeons were subjected to a series of procedures in which the key-peck's effects ranged from immediate, differential food reinforcement, through delayed reinforcement, the production of stimulus changes with and without probable secondary reinforcement, the prevention of food presentation ("food-avoidance"), to extinction. Neither primary nor secondary food reinforcement appeared to be essential for the maintenance or acquisition of key pecking. The food-avoidance contingency failed to suppress responding in any subject. Only complete extinction, when pecking produced neither food nor stimulus changes, eliminated all pecking for most subjects. A combination of stimulus-change reinforcement and food reinforcement appeared to account for the results, but only if it could be assumed that the presence of food in a procedure enhanced the reinforcing power of stimulus change, whether or not the food was also dependent upon responding. Such an interaction between reinforcers may be involved in the phenomenon of autoshaping.