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Biomedical subjects

V Johnson

Publications and source records attributed to V Johnson.

At least 37 records · Page 2Linked to original sources

The effects of managed care on physician and clinical integration in hospitals.

OBJECTIVE: To empirically estimate the effects that managed care has had on physician and clinical integration in urban hospitals. DATA SOURCES: The 1993 Hospital-Physician Relationship Survey conducted for the Prospective Payment Assessment Commission, augmented with data from a variety of secondary sources. The entire 1,495 responding hospitals were used to construct measures of integration; 591 responding hospitals in urban areas were used for the managed care analysis. STUDY DESIGN: Factor analysis was used to reduce 23 integration variables into 5 physician and 3 clinical integration factors. Two-stage least-squares regression techniques were used to estimate the effects of endogenous managed care. Models were estimated for all urban hospitals and for hospital subsets based upon ownership, multi-hospital system status, and teaching. PRINCIPAL FINDINGS: Other things equal, physician involvement in hospital management and governance increased with managed care involvement; to a lesser degree, the use of physician organization arrangements and other joint ventures also increased. Practice management and support services were lower in hospitals with high managed care activity. Larger hospitals, investor owned, system, and non-teaching hospitals had larger managed care revenues. Managed care revenues were lower in more concentrated hospital markets. CONCLUSIONS: The relationship between managed care and physician and clinical integration is relatively modest. Much of the realignment under managed care has been limited to certain types of efforts. Those efforts can best be described as foundation-building rather than comprehensive or fundamental.

Data Collection↗

Problem drinking from young adulthood to adulthood: patterns, predictors and outcomes.

OBJECTIVE: Many young adults engage in heavy or problem drinking, but it is unclear who will continue problem drinking into adulthood. This study followed a general population sample in order to study patterns of problem drinking over time, to identify differences among drinking groups, to test a model differentiating youth-limited from developmentally-persistent problem drinkers, and to examine adult outcomes. METHOD: Data were from the Health and Human Development Project; subjects (N = 1,073) were in three age cohorts (age 18-25; age 21-28; age 24-31). Based on use and consequences data from two assessment intervals, cluster analyses were performed. RESULTS: Cluster analyses yielded four drinking groups: youth-limited problem drinkers, stable moderate drinkers, stable low drinkers and developmentally-persistent problem drinkers. Rates of youth-limited problem drinking peaked in the middle cohort and rates of developmentally-persistent problem drinking decreased in the oldest cohort. Discriminant analysis revealed that developmentally-persistent problem drinkers in each age cohort are more likely to be male, to show high disinhibition, and to experience a high level of problem behaviors. Youth-limited problem drinkers were similar to developmentally-persistent problem drinkers on many young adult characteristics and adult outcomes. Developmentally-persistent problem drinkers in each age cohort continued to show higher levels of problem behaviors in adulthood than youth-limited problem drinkers. CONCLUSIONS: Most young adults show continuity of drinking patterns. Although developmentally-persistent problem drinkers did not differ from youth-limited problem drinkers in adopting adult roles, their continued experience of many problem behaviors suggests that they fail to adopt the role of greater conventionality in adulthood.

Adolescent↗

Relationship between a self-reported health questionnaire and laboratory tests at initial office visits.

BACKGROUND: Dental patients routinely complete a medical questionnaire and have an oral interview during their initial visit, but may have undiagnosed systemic problems which can affect their dental treatment. METHODS: Thirty-nine consecutive patients referred for a periodontal evaluation completed a medical questionnaire and an oral interview. They were referred to a hospital laboratory for an urinalysis, complete blood count, and a standard blood chemistry panel. RESULTS: The self-reported medical history responses were compared with the laboratory data and several abnormalities were noted. Abnormal levels were found with cholesterol, (26/39 patients, 67%); triglycerides, (13/39, 33%); glucose, (6/39, 15%); eosinophils, (18/39, 46%); and monocytes, (10/39, 26%). Smokers (17/39, 44%) had a higher number of abnormal levels or percentages of cholesterol, triglycerides, basophils, lymphocytes, eosinophils, and monocytes. Gender differences were seen in elevated triglyceride levels, abnormal aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and self-reported cardiovascular disease. CONCLUSIONS: This study demonstrated that many patients are unaware of their current medical status and a significant number had undiagnosed abnormalities.

Adult↗

A comparison of the genetic pathways involved in the pathogenesis of three types of colorectal cancer.

Patterns of allele loss (loss of heterozygosity, LOH) have been studied in order to investigate the genetic pathways involved in the pathogenesis of three types of colorectal cancer (CRC): sporadic CRC without replication errors (RER-) (32 cases); sporadic RER+ CRC (23 cases); and ulcerative colitis-associated CRC (UCACRC) (16 cases). Each tumour was assessed for allele loss at ten microsatellite markers which map close to known or putative tumour-suppressor genes: APC (5q21-q22); DCC (18q21.1); 1p35-p36; p16 (9p21); 22q; 8p; E-cadherin (16q22.1); beta-catenin (3p22-p21.3); RB1 (13q14.1-q14.2); and HLA. Overall, high frequencies of allele loss (> 30 per cent) were found near DCC (42 per cent), p16 (38 per cent), 22q (37 per cent), 1p35-p36 (34 per cent) and APC (31 per cent), and low frequencies (< 20 per cent) near RB1 (16 per cent) and E-cadherin (13 per cent). LOH near beta-catenin, HLA, and on 8p occurred at frequencies between 20 and 30 per cent. The overall frequency of allele loss did not differ among the three tumour groups, but some variation was seen at individual loci. There was a significantly higher frequency of LOH at 1p35-36 in RER+ tumours compared to RER- tumours. Allele loss at this site was also associated with a more advanced Dukes' stage at presentation. In addition, RER- tumours showed a higher frequency of allele loss at p16 than RER+ tumours. No significant difference existed at any locus between the frequency of LOH in sporadic CRC and in UCACRC. Pairwise analysis showed a negative association between LOH at APC and DCC, and between LOH at chromosome 22p and p53 overexpression. Thus, there may be specific differences between the mutation spectra of RER+ and RER- CRCs, but there are large degrees of overlap among the underlying genetic pathways of these cancers and UCACRCs.

Adult↗

Individually determined postpartum magnesium sulfate therapy with clinical parameters to safely and cost-effectively shorten treatment for pre-eclampsia.

OBJECTIVE: The purpose of this study was to investigate the safety of treating pre-eclampsia with magnesium sulfate, with clinical determinants used for drug discontinuation. STUDY DESIGN: One hundred sixty-eight patients were enrolled. After delivery, women with mild pre-eclampsia received a minimum of 6 hours of intravenous magnesium sulfate, whereas women with severe pre-eclampsia received a minimum of 12 hours. Magnesium sulfate was discontinued in the absence of clinical symptoms associated with spontaneous diuresis, minimal protein by urinary dipstick, and satisfaction of predetermined blood pressure criteria. RESULTS: Patients with mild pre-eclampsia required significantly less magnesium sulfate (mean 9.5 +/- 4.2 hours) than did those with severe pre-eclampsia alone (mean 16 +/- 5.9 hours); pre-eclampsia superimposed on chronic hypertension (mean 16 +/- 5.8 hours); or hemolysis, elevated liver enzyme, and low platelet count syndrome (mean 20 +/- 6.7 hours). With this protocol there was no eclampsia, and recovery room time was reduced by 50%. CONCLUSION: Individual determination of postpartum magnesium sulfate therapy for pre-eclampsia appears to be a safe approach that carries minimal risk of eclampsia.

Adolescent↗

Interlaboratory concordance of DNA sequence analysis to detect reverse transcriptase mutations in HIV-1 proviral DNA. ACTG Sequencing Working Group. AIDS Clinical Trials Group.

Thirteen laboratories evaluated the reproducibility of sequencing methods to detect drug resistance mutations in HIV-1 reverse transcriptase (RT). Blinded, cultured peripheral blood mononuclear cell pellets were distributed to each laboratory. Each laboratory used its preferred method for sequencing proviral DNA. Differences in protocols included: DNA purification; number of PCR amplifications; PCR product purification; sequence/location of PCR/sequencing primers; sequencing template; sequencing reaction label; sequencing polymerase; and use of manual versus automated methods to resolve sequencing reaction products. Five unknowns were evaluated. Thirteen laboratories submitted 39043 nucleotide assignments spanning codons 10-256 of HIV-1 RT. A consensus nucleotide assignment (defined as agreement among > or = 75% of laboratories) could be made in over 99% of nucleotide positions, and was more frequent in the three laboratory isolates. The overall rate of discrepant nucleotide assignments was 0.29%. A consensus nucleotide assignment could not be made at RT codon 41 in the clinical isolate tested. Clonal analysis revealed that this was due to the presence of a mixture of wild-type and mutant genotypes. These observations suggest that sequencing methodologies currently in use in ACTG laboratories to sequence HIV-1 RT yield highly concordant results for laboratory strains; however, more discrepancies among laboratories may occur when clinical isolates are tested.

Codon↗

Managed care and processes to integrate physicians/hospitals.

This article describes the extent to which hospitals use different integrative processes to assimilate physicians and assesses the extent to which their use is associated with managed care penetration and hospital characteristics. Results from a national survey of 1,495 community hospitals indicate that these integrative processes are quite prevalent. The use of integrative processes tends to be more prevalent in hospitals that are large, urban, involved in teaching, and members of hospitals systems. Use of particular integrative processes also appears to be associated with different thresholds of managed care penetration.

Delivery of Health Care, Integrated↗

Physician and clinical integration among rural hospitals.

The pressures for closer alignment between physicians and hospitals in both rural and urban areas are increasing. This study empirically specifies independent dimensions of physician and clinical integration and compares the extent to which such activities are practiced between rural and urban hospitals and among rural hospitals in different organizational and market contexts. Results suggest that both rural and urban hospitals practice physician integration, although each emphasizes different types of strategies. Second, urban hospitals engage in clinical integration with greater frequency than their rural counterparts. Finally, physician integration approaches in rural hospitals are more common among larger rural hospitals, those proximate to urban facilities, those with system affiliations, and those not under public control.

Analysis of Variance↗

Follow-up of sporadic cases of food-borne infection: comparison of a postal questionnaire with a personal visit.

The aim of the study was to evaluate the follow-up of sporadic cases of suspected food-borne illness by either a postal questionnaire or a personal visit by environmental health staff. This was achieved by comparing the practice in two authority areas within the West Pennine Health Authority in the north west of England. We included all identified cases of suspected food poisoning, campylobacteriosis, cryptosporidiosis, salmonellosis and dysentery occurring in the district between 1 July and 30 September 1996. The main outcome measures were: (1) the proportion of all cases which were successfully followed-up by each method; (2) the timeliness of follow-ups; (3) qualitative estimation by environmental health staff of the data obtained. Visiting by environmental health staff was successful in obtaining information from 76.3% (106/139) of cases, while the postal questionnaires elicited a 52% (50/96) response rate. We found that 70.5% of visits occurred within one week of notification. Although 69.8% (67/96) of questionnaires were issued within one week of notification, only 16% of replies to the questionnaire were received within this period. The information provided on the returned questionnaires was found by environmental health staff to be generally as useful as that obtained by visiting.

Adolescent↗

Neuroleptic malignant syndrome associated with olanzapine.

OBJECTIVE: The aim of the present paper is to report a case of Neuroleptic Malignant Syndrome (NMS) occurring 2 days after olanzapine was added to the treatment regimen of an elderly patient with Schizoaffective Disorder. The patient had a previous history of NMS associated with risperidone. CLINICAL PICTURE: Two days after commencement of olanzapine, the patient presented in a stuporous state with dysarthria and increased muscle tone with cogwheeling. His level of consciousness fluctuated over the following 24 h with worsening rigidity, the onset of a mild fever, tachycardia and elevated blood pressure. Biochemical screening revealed markedly elevated creatine kinase. TREATMENT: Olanzapine was ceased and intravenous fluid replacement commenced. Hourly physical observations were instigated, as was regular serum monitoring of creatine kinase level. OUTCOME: Over the subsequent 48 h, there was gradual clinical improvement with resolution of dysarthria, ataxia, rigidity and fever. The patient was returned to the psychiatric ward 3 days after his admission to the medical ward. CONCLUSIONS: Olanzapine therapy can be associated with NMS. To our knowledge, there are no previous reports of this in the literature.

Aged↗

The spread of state any willing provider laws.

OBJECTIVE: To describe the growth of any willing provider (AWP) and freedom of choice (FOC) laws applicable to managed care firms and to explore empirically the determinants of their enactment. STUDY SETTING: A 1996 compendium of state laws and state-level data from the 1991-1994 period. STUDY DESIGN: Pooled cross-section time-series logistic regression of the decision to enact various types of AWP and FOC laws. Analysis uses a public choice framework to examine enactment. Key variables include proxy measures of proponent and opponent strength and the political environment. PRINCIPAL FINDINGS: The model works well for laws affecting hospitals, but performs poorly for physician and pharmacy laws. More providers are associated with the enactment of AWP and FOC laws. More large employers are associated with a reduced likelihood of enactment of some forms of the laws but not others. Conservative states are more likely to enact laws limiting selective contracting with hospitals and physicians. States with greater interparty competition are also more likely to adopt some types of legislation. CONCLUSIONS: The empirical results generally are consistent with the view that AWP and FOC laws are often enacted as a defensive strategy on the part of providers, but additional research is needed to provide a more definitive assessment of the determinants of these laws. Suggestions for future research are provided.

Decision Support Techniques↗

Treatment of Wilson's disease with zinc: XIV. Studies of the effect of zinc on lymphocyte function.

Although administration of zinc to human subjects has been reported to interfere with lymphocyte function, this single report has never been confirmed or refuted. We have developed zinc as a lifelong therapy for patients with Wilson's disease. Interference with lymphocyte function occurring as a side effect of zinc therapy could produce serious problems in our patients. We evaluated lymphocyte mitogenic response and natural killer cell activity in patients with Wilson's disease treated for 5 years or longer with zinc, in comparison with normal controls, and found no differences. In a second study, we evaluated these same parameters in patients with Wilson's disease before and after 1 year of zinc therapy, and again found no significant differences. We have seen no indications of immune suppression or increased susceptibility to infections in our patients, who have now been treated with zinc for up to 15 years. We conclude that any side effects from compromised lymphocyte function caused by administration of zinc are not of concern to patients with Wilson's disease.

Copper↗

MALDI-MS as a monitor of the purification and folding of synthetic eclosion hormone.

Analogues of the small protein Manduca sexta eclosion hormone (62 amino acids) were synthesized by Fmoc solid-phase methodology. Matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) was used to analyze the products of the syntheses and this information was used to design an efficient purification scheme. MALDI-MS was used to monitor the target products through purification and it was also used to monitor folding of the purified materials. The folded EH analogues were shown to be biologically active proteins with an in vivo bioassay using pharate adult moths, Heliothis virescens.

Amino Acid Sequence↗

Wilson's disease: presymptomatic patients and Kayser-Fleischer rings.

PURPOSE: We evaluated patients with Wilson's disease to determine (1) whether presymptomatic patients who have Kayser-Fleischer (K F) rings demonstrate a more significant alteration of copper metabolism than those who do not have K F rings, and (2) whether presymptomatic patients have smaller K F rings than symptomatic Wilson's disease patients. METHODS: Thirty-two patients with presymptomatic Wilson's disease were retrospectively analyzed. Sixteen of these had received no prior anti-copper therapy and underwent testing for baseline copper metabolism (24-hour urine copper, liver copper, and plasma ceruloplasmin). Quantitative measurements of K F rings were made for the group of untreated presymptomatic patients and a control group of symptomatic Wilson's disease patients. RESULTS: We hypothesized that the 24-hour urine copper, in particular, would correlate with the presence of a K F ring. However, no significant difference was found between any of the baseline copper variables for presymptomatic patients who had K F rings compared to those who did not. K F rings of presymptomatic patients were found to be significantly smaller than K F rings of patients with symptomatic Wilson's disease (p < 0.05). CONCLUSIONS: While this study does not show any relationship between urinary copper excretion and the presence of K F rings, it suggests that the larger K F ring size correlates with Wilson's disease severity.

Adolescent↗

Treatment of Wilson disease with ammonium tetrathiomolybdate. II. Initial therapy in 33 neurologically affected patients and follow-up with zinc therapy.

OBJECTIVE: To test the efficacy and toxic effects of ammonium tetrathiomolybdate in the initial treatment of a relatively large series of patients with neurologic symptoms and signs caused by Wilson disease. Two key aspects of efficacy are to preserve the neurologic function present at the onset of therapy and to maximize the opportunity for long-term recovery. DESIGN: An open study of 33 patients treated for 8 weeks each, including further follow-up data on the original 17 patients. Neurologic function was evaluated by frequent quantitative neurologic and speech pathology examinations. Several copper-related variables were studied to evaluate the effect of the drug on copper, and several biochemical and clinical variables were studied to evaluate potential toxic effects. Patients were then followed up at yearly intervals, with follow-up periods of 1 to 8 years reported. SETTING: A university hospital referral setting. INTERVENTION: Patients were generally treated for 8 weeks with tetrathiomolybdate, followed by zinc maintenance therapy. MAIN OUTCOME MEASURES: Neurologic function was evaluated by quantitative neurologic and motor speech examinations and magnetic resonance imaging scans of the brain. RESULTS: During the 8 weeks of tetrathiomolybdate administration, only 1 of the 33 patients showed deterioration in neurologic function. Copper status and potential further toxic effects were generally well controlled quickly. Evaluation of data from individual patients revealed evidence of a toxic side effect in only 1 patient, who exhibited reversible anemia. During the ensuing period of follow-up of 1 to 6 years, neurologic recovery in most patients was good to excellent. CONCLUSIONS: Tetrathiomolybdate appears to be an excellent form of initial treatment in patients with Wilson disease who present with neurologic symptoms and signs. In contrast to penicillamine therapy, initial treatment with tetrathiomolybdate rarely allows further, often irreversible, neurologic deterioration.

Adolescent↗

Trauma patients: an analysis of rural ambulance trip reports.

This study summarizes all 2,550 trauma-related rural ambulance trip reports filed for the period January 1 through December 31, 1991 from the 12 rural counties surrounding Augusta, Georgia. There were 13.1 trauma-related ambulance runs per 1,000 population. Nearly one third of all rural ambulance runs are trauma related. Severe trauma constituted less than 8.0% of trauma cases. Forty-one cases died at the scene and 19 additional cases died from any cause within 30 days of transport. The mean response time was 8.5 minutes and in 90% of all rural trauma runs the ambulance arrived in 17 minutes or less. Only 51.5% of runs had a rural hospital as a destination, 14.2% went directly to a trauma center, and nearly 20% to another urban hospital. Of the 71 severe trauma cases received by ambulance, rural hospitals transferred out only 13 cases, most of these to the regional trauma center. Of the 47 trauma cases transferred to the trauma center, 33 were not severe.

Adolescent↗

Simplifying the assessment of rural emergency medical service trauma transport.

OBJECTIVES: The authors determine whether assessments of effects of rural emergency medical services (EMS) system characteristics on trauma outcomes using patient-level data are biased significantly if the Injury Severity Score (ISS) is not available. METHODS: Data are taken from ambulance trip reports merged with the trauma registry data for the Georgia EMS region VI trauma center hospital, located in Augusta. All 294 trauma patients for the rural counties surrounding Richmond County for the calendar year 1991 who were not dead at the scene and who were treated at the trauma center are included. A 20% random sample of trauma patients from Richmond county from May 1991 to September 1991 not dead at the scene and treated at the trauma center yielded an additional 96 cases. Excluding 43 patients with missing data yields 347 trauma cases with 18 trauma deaths. A logistic regression model for trauma mortality is estimated using the Revised Trauma Score, ISS, type of trauma, and patient age (analogous to the standard Trauma Related Injury Severity Score model). The predicted probability of patient mortality from this model is compared with the predicted probability of mortality when the logistic regression model omits ISS. Correlations between the difference in predicted probability (ie, the error in predicted probability associated with the omitted ISS variable) and EMS system characteristics are determined. RESULTS: Although ISS adds to the predictive power of the trauma outcome model, the errors in predicted probabilities associated with the omission of ISS generally are small and uncorrelated with patient or EMS system characteristics, with the exception of patient gender. CONCLUSIONS: In rural settings, where a patient's ISS generally is not available, studies of rural EMS system characteristics and trauma outcomes may use Revised Trauma Score, patient age, and type of trauma to control for expected survival. The patient's ISS does not appear to be essential, at least for the rural area analyzed in this study.

Emergency Medical Services↗