Client flow through the Women, Infants, and Children Public Health Program.

The Women, Infants, and Children (WIC) Program, managed by the county boards of health, provides nutrition, limited physical examinations, and food vouchers for pregnant women and for children with nutritional deficiencies. Because federal guidelines for the WIC program leave little maneuvering room to improve the delivery of services, we analyzed the client flow through a WIC clinic in the Atlanta metropolitan area to determine how that flow could be managed more efficiently. The challenge facing the WIC clinic was to increase the efficiency of their operation in an environment characterized by resource constraints, rigid regulations, and dysfunctional client behavior. In a limited physical space, the WIC clinic was expected to provide a number of sequential services to a client population that failed to arrive or arrived late 40 percent-50 percent of the time. The provision of services was further complicated by walk-ins, which were not only common but, according to federal guidelines, also must be accommodated. To analyze the clinic's problem, we used the General Purpose Simulation System for personal computer (GPSS/PC) to simulate client flow through the clinic. Estimates of the average amount of time a client spent in the clinic as well as average waiting times at each station and clerk and nurse utilization rates were generated assuming a variety of staffing levels. For comparison purposes, each version of the model was run with a 20-minute time lag before a late appointment was filled, and then a one-minute lag. The data used for the simulation were collected by clinic personnel during February 1994. It included the number of clerks and nurses available; the waiting time to see clerks and nurses for walk-ins and appointments; the waiting time to get WIC vouchers; the number of appointments met; the number of appointments missed; and the total time in the clinic for walk-ins and appointments. In all three versions of the model that were estimated, the results of the simulations revealed that reducing the time before a late appointment was filled significantly decreased the time spent in the clinic, on average, for all clients. Furthermore, the time spent waiting for both clerks and nurses decreased, the utilization of the clerks decreased, and the utilization of the nurses increased in two of the three estimations.

Effects of chosen versus assigned jobs on the work performance of persons with severe handicaps.

We evaluated the effects of several choice-related variables on the work performance of adults with severe handicaps. After assessing client work preferences, three choice-related situations were presented: (a) providing clients with the opportunity to choose a work task, (b) assigning a preferred task, and (c) assigning a nonpreferred task. Results indicated that clients attended to work tasks almost twice as much when they chose their tasks and when assigned to work on preferred tasks versus when assigned to work on nonpreferred tasks. Results are discussed regarding the need to assess systematically the effects of choice-related variables.

Lindholm blood coagulation test values of some glow-discharge polymer surfaces.

An ultrathin layer (approximately 500A) of glow-discharge polymer that is strongly bonded to a polymer film substrate can be sued to modify the blood compatibility of the polymer surface. Glow-discharge polymers of tetrafluoroethylene, hexamethyldisiloxane, ethylene-N2, and allene-N2-H20 were deposited onto Mylar film and subjected to Lindholm whole blood coagulation tests. Lindholm tests were performed in a manner that permitted statistical analysis. This was done by repeating the preparation of samples as well as the coagulation tests a number of times. Results showed that Lindholm tests values were useful in obtaining information pertinent to compatibility of surfaces with fresh human blood and to reproducibility of sample preparation by glow-discharge polymerization. The study also revealed that glow-discharge polymerization is a promising method to impart blood compatibility without altering other bulk properties of substrate polymers.

Ultrathin coating by plasma polymerization applied to corneal contact lens.

Plasma coating (deposition of polymer under the influence of plasma) is utilized to modify the surface properties of corneal contact lens. An ultrathin layer (thickness of roughly 200 A) of plasma polymer of acetylene/H20/N2 is applied to poly(methyl methacrylate) (PMMA) corneal contact lenses. The surface becomes highly wettable with water compared to uncoated lens. When coated and uncoated contact lenses are placed on rabbit eyes, a remarkable difference in accumulation of mucous matter is observed. With the control lenses, the accumulation of mucous matter in a week is sufficient to affect the optical clarity of the lenses, whereas the coated lenses show no change after three months continuous wearing. The comparative degree of adhesion of the corneal epithelium cells onto glass, modified glass, PMMA, and coated PMMA surfaces is studied using tissue cultures and phase contrast microscopy. The coated PMMA surface exhibits a degree of tissue adhesion lower than that of control PMMA and higher than that of glass surface, and no sign of toxicity of the coated surface is observed by the tissue cultures.