The productivity of physician assistants and nurse practitioners and health work force policy in the era of managed health care

Managed care is spreading rapidly in the United States and creating incentives for physician practices to find the most efficient combination of health professionals to deliver care to an enrolled population. Given these trends, it is appropriate to reexamine the roles of physician assistants (PAs) and nurse practitioners (NPs) in the health care workforce. This paper briefly reviews the literature on PA and NP productivity, managed care plans' use of PAs and NPs, and the potential impact of PAs and NPs on the size and composition of the future physician workforce. In general, the literature supports the idea that PAs and NPs could have a major impact on the future health care workforce. Studies show significant opportunities for increased physician substitution and even conservative assumptions about physician task delegation imply a large increase in the number of PAs and NPs that can be effectively deployed. However, the current literature has certain limitations that make it difficult to quantify the future impact of PAs and NPs. Among these limitations is the fact that virtually all formal productivity studies were conducted in fee-for-service settings during the 1970s, rather than managed care settings. In addition, the vast majority of PA and NP productivity studies have viewed PAs and NPs as physician substitutes rather than as members of interdisciplinary health care teams, which may become the dominant health care delivery model over the next 10-20 years.     

Behavioral and biomedical research: a partnership for better health

In the last decade, global use of contraceptive methods has increased. About 50% of couples of childbearing age use a modern contraceptive method. This evolution and a positive change in attitude towards male contraception has encouraged research in fertility regulation to enlarge and to improve acceptance of the contraceptive mix. Current injectable contraceptives interfere with the menstrual cycle. Research is exploring ways to minimize such secondary effects by reducing the total hormone dose and by changing the way the active product is delivered (e.g., microspheres). An injectable prototype is an analogue of levonorgestrel (HRP 002). A new IUD is made of leather suspended by a nylon suture which has been inserted into the uterine muscle. RU-486, often used to interrupt early pregnancy, is being tested as an oral contraceptive (OC). It inhibits secretion of gonadotropins and ovulation. It holds promise as an OC with no estrogen component. Since it also inhibits endometrial development and thus prevents implantation, it may someday be used for emergency contraception (i.e., postcoital contraception). New contraceptive implants under study include Norplant RII (2 rods of levonorgestrel lasting for 3 years), Implanon (desogestrel), and Capranor (biodegradable implant lasting 2 years). The female condom consists of a flexible polyurethane sheath with a flexible ring at each end. It has the potential to protect against sexually transmitted diseases since it covers the labial lips and is impermeable to HIV. France and Switzerland have both approved its use. It will enter the UK market at the end of the year. Approval for marketing has been sought in the US.     

Psychologist–physician partnership in a medical specialty screening clinic.

Describes the development of a headache screening clinic in which psychologists participate with neurologists in the initial patient evaluation, using brief screening questionnaires and interviews. The majority of patients assessed in this clinic experienced clinically significant emotional distress, although only a minority of these patients felt a need for psychological intervention. By combining psychological screening with initial medical evaluation, emotionally disturbed individuals who present with physical complaints can be rapidly identified and their defensiveness about referral for psychological/psychiatric intervention can be minimized. Psychologists' psychometric screening instruments and their interviewing skills can contribute significantly to optimal utilization of health care services. Three case examples are given. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychology and mental health: An enduring partnership.

Discusses the relationship between psychology and the National Institute of Mental Health's (NIMH's) funding of research in the behavioral sciences and the diagnosis, treatment, and prevention of mental illness. It is pointed out that, despite the fears of biological reductionism, the NIMH is determined to maintain a balanced program across the broad spectrum of its efforts. The funding of current research efforts in a variety of areas is outlined. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nurse practitioners, certified nurse midwives, and physician assistants in California

A monoclonal antibody (MAb) targeting human hepatocellular carcinoma (HCC) has been produced by immunizing BALC/c mice with HCC SMMC-7721 cells. Solid phase enzyme-linked immunoabsorbent assay (ELISA) analysis showed that this mAb (mAb 95) was reactive with human HCC cell lines and tumor biopsies, but not tumors of other origin or normal tissues tested. Immuno-gold labeling and flow cytometry indicated that mAb 95 bound specifically to HCC cell membrane protein. Western blot analysis showed mAb 95 reacts only with HCC cell lysates, but not with 10 different human normal tissue lysates. The approximate molecular size of the reactive proteins were 40,000 and 60,000 daltons. The specificity of mAb 95 indicates it may be a potential candidate for a targeting agent in HCC immunotherapy or immunodetection.     

Mental health and the workplace: An interchangeable partnership.

Mental health is an important component of occupational health. The National Institute for Occupational Safety and Health recognizes psychological disorders as one of the 10 leading work-related diseases and injuries (J. D. Millar, 1984). Job-related stress is receiving an increasing amount of public attention, and several studies indicate that stress-related conditions are among the most important health problems of the 1990s for people at work and outside of work. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of surgical physician assistants on the delivery of modern healthcare

In 15-day-old control and vehicle-treated rats, the evening rise of the pineal N-acetyltransferase occurred at the same time as in their mothers, whereas in 5-day-old pups, the rise occurred by 2-3 hr earlier. Four-day administration of melatonin in the late day phase advanced the N-acetyltransferase rise in 15-day-old rats as compared with the rise in the vehicle-treated animals; a slight melatonin induced phase advance in 5- and 27-day-old rats was not significant. The data indicate that the newborn rat's circadian pacemaker controlling the rhythmic N-acetyltransferase rise may be entrained by exogenous melatonin. It appears, however, that the maternal melatonin transferred via milk cannot entrain the pup's pacemaker by phase advancing it, since the N-acetyltransferase rise in the pups begins earlier or at the same time as maternal melatonin production driven by the N-acetyltransferase rhythm.     

Characteristics of patient visits to nurse practitioners and physician assistants in hospital outpatient departments

Amprolium was successfully used to induce cerebrocortical necrosis (CCN) in dromedary racing camels, only when they were fed on a barley diet. Camels which were fed on hay ad libitum did not suffer form CCN, although their thiamine pyrophosphate (TPP) reached similar levels as in camels fed on barley. The reason for this phenomenon is discussed. Five camels which suffered from CCN had TPP values of 80-115% and were euthanized on humane grounds when they were in lateral recumbency. Pathohistological investigations revealed a polioencephalomalacia of the dorsal cerebral cortex with oedema and status spongiosus. Cerebral autofluorescence was observed under ultraviolet light. The major clinicopathological changes were a slight anemia and a decreased potassium value whereas glucose, muscle enzymes, leucocyte counts and differential counts were elevated. A TPP effect of 12% was found during this study in healthy dromedary racing camels and symptoms were observed when TPP values reached 80-115%. The test is now being widely used during the camel racing season.     

An inter district quality partnership: the experience of a large rural health service

The interleukin-2 receptor (IL-2R) gamma chain (gamma c chain) is shared by IL-4R, IL-7R, IL-9R, and IL-15R and plays an important role in regulation of the immune system. However, its regulation in monocytic cell lines has not been well clarified. We examined the expression and regulation of the IL-2R alpha, IL-2R beta, gamma c chain, IL-4R and IL-7R mRNA in a human monoblastic leukemia cell line, THP-1. Unstimulated THP-1 cells constitutively expressed a low level of gamma c chain and IL-4R mRNA. Phorbol myristate acetate (PMA) induced macrophage-like differentiation and up-regulated the gamma c chain mRNA expression in THP-1 cells. This effect of PMA was suppressed by the protein kinase inhibitors H-7 and staurosporine. PMA did not affect the expression of the other IL-R mRNAs examined. 1 alpha, 25(OH)2D3 and interferon-gamma also induced differentiation of THP-1 cells, but these reagents did not affect the expression of the IL-R mRNAs in THP-1 cells. These findings suggest that the expression of the gamma c chain mRNA is regulated by the PMA-dependent pathway and is not associated with that of the other IL-R mRNAs.     

Can health care assistants replace student nurses?

Quantitative trait loci (QTLs) affecting body weight were investigated in the backcross population derived from diabetic BB/OK and spontaneously hypertensive rat (SHR). The F1 hybrids were backcrossed onto BB/OK rats, and QTL analysis was performed with the resulting backcross population on chromosomes 1, 3, 4, 10, 13 and 18. According to the stringent threshold for a lod score of 3.0, markers on chromosomes 1 and 4 were found to be linked with body weight. The QTL with a peak lod score (3.3) on chromosome 1 for a male population was located within the region flanked by loci Igf2 and D1Mgh12. On chromosome 4, linkage between the body weight and the region around the Npy locus was observed (lod score 3.1). The existence of the QTL on chromosome 4 affecting body weight was confirmed by congenic BB.LL rats, carrying chromosomal region of SHR (D4Mit6-Npy-Spr) on the genetic background of the BB/OK rat.     

Understanding the interactions between physician assistants and their supervising physicians in the provision of patient care

Both contractile and relaxant responses to tetrapentylammonium ions (TPA+) were studied in rat isolated mesenteric artery. TPA+ (5-10 micromol/l) caused a sustained increase of muscle tension. The contractile effect of TPA+ (10 micromol/l) was dependent upon the presence of extracellular Ca2+ but independent of the presence of endothelium. TPA+ (10-50 micromol/l) induced biphasic contraction, and the amplitude of peak and sustained tension decreased with increasing TPA+ concentration. TPA+ (100-300 micromol/l) only produced monophasic contraction. TPA+ (50 micromol/l) abolished the transient contraction induced by caffeine (10 mmol/l) or phenylephrine (1 micromol/l) in the absence of extracellular Ca2+. Nifedipine and verapamil concentration-dependently reduced the TPA+-induced contraction with respective IC50 values of 1.34 +/- 0. 24 and 9.46 +/- 1.36 nmol/l, these values were similar to 1.35 +/- 0. 21 and 16.07 +/- 1.71 nmol/l, respectively, for the inhibitory effects of nifedipine and verapamil on the high K+ (60 mmol/l)-induced contraction. TPA+ (>10 micromol/l) concentration-dependently reduced the phenylephrine (1 micromol/l)-, U46619 (30 nmol/l)-, endothelin I (10 nmol/l)- and high K+ (60 mmol/l)-induced sustained tension with respective IC50 values of 53. 7 +/- 9.5, 31.9 +/- 5.3, 30.9 +/- 3.4 and 20.9 +/- 2.8 micromol/l. The present results indicate that TPA+ at low concentrations could contract the arterial smooth muscle probably through promoting Ca2+ influx. At higher concentrations (>20 micromol/l), TPA+ relaxes arterial smooth muscle probably through inhibition of both nifedipine-sensitive Ca+ channels and internal Ca2+ release. TPA+, unlike other quaternary ammonium ions, could therefore act at multiple sites in arterial smooth muscle.     

The partnership model: working with individuals, families, and communities toward a new vision of health

A novel irreversible 5-HT1A receptor binding ligand, NCS-MPP (4-(2'- methoxy-phenyl)-1-[2'-(N-2"-pyridyl)-p-isothiocyanobenzamido]- ethyl-piperazine), based on the new 5-HT1A receptor antagonist p-MPPI (4-(2'-methoxy-phenyl)-1-[2'-(N-2"-pyridyl)-p-iodobenzamido]-ethyl -piperazine ), was synthesized, and its binding characteristics were evaluated using in vitro homogenate binding with rat hippocampal membranes. The Ki value of NCS-MPP was estimated to be 1.8 +_ 0.2 nM using analysis of concentration-dependent inhibition for the binding of [125I]p-MPPI to 5-HT1A receptors. NovaScreen of NCS-MPP showed low to moderate binding affinities to alpha-1, alpha-2-adrenergic and 5-HT2 receptors, with Ki values of 350, 420, and 103 nM, respectively. These data strongly suggest that the ligand bound to 5-HT1A receptors with high affinity and high selectivity. Irreversible inhibition of [125I]p-MPPI binding by NCS-MPP following a 5 min incubation at room temperature was concentration dependent; the inhibition increased to 50% at a concentration less than 10 nM, and became more pronounced (90%) at 400 nM. Under similar assay conditions, NCS-MPP was significantly less efficient in irreversibly inhibiting agonist ligand [125I]8-OH-PIPAT binding to 5-HT1A receptors at lower concentrations (<10nM). After pretreatment of membranes with a low concentration of NCS-MPP (2nM), there was an apparent loss of [125I]p-MPPI binding sites, as expected, but no change in the binding affinity (Kd) was observed. However, the significant increase in Kd at a higher concentration of NCS-MPP (50 nM) indicated that there may be a secondary alkylation site, which may not be directly involved in p-MPPI binding to receptors; nevertheless, it would lead to an increased Kd value. The availability of an irreversible ligand, NCS-MPP, may provide a useful tool for studies of 5-HT1A receptors in the central nervous system.