Lead exposure in battery-factory workers is not associated with anemia

Anemia is a manifestation of lead toxicity. However, there are conflicting reports of its prevalence among lead-exposed workers, and it is uncertain whether they should be monitored by periodic hemoglobin (Hb) examinations. To explore the relationship between Hb and lead exposure, we examined the correlation between Hb, blood lead (PbB), and zinc protoporphyrin (ZPP) levels in 961 blood samples obtained from 94 workers in a lead-acid battery plant in Israel between 1980 and 1993. Blood lead levels exceeded 60 micrograms/dL (2.90 mumol/L) in 105 (14%) of the blood samples. The correlation between PbB and logZPP was 0.594. Hb levels did not correlate with PbB or ZPP. We conclude that (a) periodic Hb determinations are not a useful indicator of lead exposure in Israeli industrial workers; (b) the discrepancies between the reported correlation between PbB and Hb levels remain unexplained and in need of further study; and (c) a finding of anemia in a person with PbB levels of up to 80 micrograms/dL should be considered to be due to lead toxicity only after other causes for anemia have been excluded.

From socialist principles to motorcycle maintenance: the origin and development of the salaried physician model in the Israeli Public Health Services, 1918 to 1998

For more than 70 years, physicians in the Israeli health care system have been employed on a fixed salary rather than on a fee-for-service basis. The present report is a brief review of the origin and development of this unique salaried physician model and its effect on the terms of physicians' employment. Archival documents were reviewed. The salaried physician model was introduced to ensure egalitarian health care for patients rather than equal payment for physicians. It was accepted by physicians because it guaranteed their employment and income. However, over the years, the salaried physician model has evolved into a complex wage scale, with multiple fringe benefits that bypass formal agreements in order to reward individual physicians. In addition, the salaried physician model has encouraged illegal private practice, which is viewed today as one of the major problems of the Israeli Public Health Services.

Patients' preferences for participation in clinical decision making: a review of published surveys

Models of doctor-patient relations vary between "paternalistic" and "informative." The paternalistic model emphasizes doctors' authority; alternative models allow patients to exercise their rights to autonomy. Published surveys indicate that most patients want to be informed about their diseases, that a proportion of patients want to participate in planning management of their illnesses, and that some patients would rather be completely passive and would avoid any information. The severity of the patients' conditions, and their being older, less well educated, and male are predictors of a preference for the passive role in the doctor-patient relationship, but demographic and situational characteristics explain only 20% or less of the variability in preferences. The only way a physician can gain insight into an individual patient's desire to participate in decision making is through direct enquiry. The ability to communicate health-related information and to determine the patients' desire to participate in medical decisions should be viewed as a basic clinical skill.

Smoking cessation and weight gain

Cigarette smokers have a lower average body weight than nonsmokers, and the cessation of smoking is associated with weight gain. Although this weight gain does not offset the health benefits of smoking cessation, it is frequently a source of concern for smokers planning to quit. The objective of our review was to estimate the risk and duration of weight gain after cessation of smoking to help physicians in counseling concerned smokers. We reviewed the literature by doing a MEDLINE search using key words for articles on the changes in body weight after smoking cessation. The retrieved data indicated that (1) the risk of weight gain is highest during the 2 years immediately following smoking cessation, and declines thereafter; (2) on average, sustained quitters gain about 5 to 6 kg in weight; (3) physical exercise, older age, higher baseline body mass index, and lower rates of smoking attenuate the degree of weight gained after smoking cessation; and (4) the evidence regarding the permanence of the expected weight gain is conflicting.

Predictive value of determinations of zinc protoporphyrin for increased blood lead concentrations

Blood lead (PbB) and red cell zinc protoporphyrin (ZPP) concentrations are widely used biomarkers for lead toxicity. It is uncertain, however, whether either or both are needed for monitoring lead exposure and how discordant PbB and ZPP values should be interpreted. We reviewed the results of PbB and ZPP determinations in 94 workers in a lead-battery plant over a 13-year period and retrieved all 807 sets of tests in which both PbB and ZPP were available, with a follow-up PbB value 6 months later. PbB exceeded 1.93 μmol/L (40 μg/dL) in 414 (51%), and 2.90 μmol/L (60 μg/dL) in 105 (14%) of the blood samples. We derived the test properties of various ZPP concentrations for concurrent “toxic” PbB concentrations, defined as ≥1.93 and 2.90 μmol/L (40 and 60 μg/dL). The results indicated that, given a population of lead-exposed workers with a 10% prevalence of PbB of ≥2.90 μmol/L (60 μg/dL), a policy of testing PbB only in those with ZPP >0.71 μmol/L (40 μg/dL) would obviate 42% of the PbB tests, but would miss about three cases with toxic PbB concentrations in every 200 workers at risk. A finding of increased ZPP concentrations with a concurrent “nontoxic” PbB was associated with an increased risk of a toxic PbB concentration 6 months later. We conclude that (a) screening by testing only ZPP does not safeguard exposed persons against lead toxicity, and (b) the frequency of PbB monitoring should be guided by estimates of the risk of future lead toxicity in individual workers.

Predictive value of determinations of zinc protoporphyrin for increased blood lead concentrations

Blood lead (PbB) and red cell zinc protoporphyrin (ZPP) concentrations are widely used biomarkers for lead toxicity. It is uncertain, however, whether either or both are needed for monitoring lead exposure and how discordant PbB and ZPP values should be interpreted. We reviewed the results of PbB and ZPP determinations in 94 workers in a lead-battery plant over a 13-year period and retrieved all 807 sets of tests in which both PbB and ZPP were available, with a follow-up PbB value 6 months later. PbB exceeded 1.93 micromol/L (40 microg/dL) in 414 (51%), and 2.90 micromol/L (60 microg/dL) in 105 (14%) of the blood samples. We derived the test properties of various ZPP concentrations for concurrent "toxic" PbB concentrations, defined as > or = 1.93 and 2.90 micromol/L (40 and 60 microg/dL). The results indicated that, given a population of lead-exposed workers with a 10% prevalence of PbB of > or = 2.90 micromol/L (60 microg/dL), a policy of testing PbB only in those with ZPP > 0.71 micromol/L (40 microg/dL) would obviate 42% of the PbB tests, but would miss about three cases with toxic PbB concentrations in every 200 workers at risk. A finding of increased ZPP concentrations with a concurrent "nontoxic" PbB was associated with an increased risk of a toxic PbB concentration 6 months later. We conclude that (a) screening by testing only ZPP does not safeguard exposed persons against lead toxicity, and (b) the frequency of PbB monitoring should be guided by estimates of the risk of future lead toxicity in individual workers.

Variability in management of symptomless microhaematuria in schoolchildren

The evaluation of incidentally detected symptomless microhaematuria in schoolchildren is controversial. Some authors advocate varying numbers of immediate tests, while others recommend investigations only in cases who develop systemic symptoms or signs, or a decline in renal function. The objective of this study was to estimate the extent to which this uncertainty affects the declared habits of practising physicians. A sample of 16 family physicians, 42 primary care paediatricians and 26 full-time hospital-based paediatric nephrologists in Israel were asked to complete a survey using a written case of a hypothetical eight-year-old boy with incidentally detected symptomless microhaematuria. Responses were received from 16 (100%), 18 (43%) and 18 (69%), respectively. The mean number of requested tests, other than follow-up examination of the urine, were 1.5 (range 0-5) for family physicians, 2.5 (1-5) for primary care paediatricians and 5.3 (2-12) for paediatric nephrologists, at an average cost of NIS 408 (US$ 136), NIS 454 (US$ 151) and NIS 860 (US$ 286), respectively. There was also a marked variability within subspecialty groups, so that some family physicians recommended more tests at a higher cost than some of the paediatric nephrologists. There was a marked and unexplained variability within and among the three groups of respondents regarding the extent of the evaluation. The main reason for this variability is probably the uncertainty about the scientifically appropriate way to approach this condition in a symptomless child.

Barriers to acceptance of medical error: the case for a teaching program (695)

There is need for a teaching programme aiming to impart a tolerance of error to undergraduate medical students. The implementation of such a programme may have to challenge the institutional norms that encourage authoritarianism, intolerance of uncertainty and denial of error. Acceptance of error is a prerequisite for its candid reporting, and reporting of errors is a prerequisite for their analysis with a view to their prevention. A curriculum on medical error may, therefore, not only help medical students cope with their future mistakes, but also reduce their frequency. Teaching intervention aiming to promote an acceptance of medical error as both inevitable and reducible may also encourage students' epistemological development by making them realize that their doubts and uncertainties are shared by their peers and instructors.

What is adequate health care and how can quality of care be improved?

Attempts to improve patient care, its increasing cost and the aggressive malpractice environment have highlighted the need for standards of professional accountability. However, current measures of quality of care have mostly been met with skepticism by the medical community. These measures have been criticized for their uncertain validity and for focusing on secondary aspects of service that measure what is minimally acceptable. The objective of this essay is to review quality improvement methods that have been reported to be feasible, effective and acceptable by practicing physicians. The successful implementation of these methods seems to be related to their being nonintrusive, nonthreatening, and based on agreed upon standards of care. We believe that these three features are essential for a continuous quality improvement process in health care.

Symptomless microhaematuria in schoolchildren: causes for variable management strategies

We reviewed published data on the frequency of underlying disorders in schoolchildren with microscopic or gross isolated haematuria (IH), and evaluated management strategies. We found five reports of microscopic IH in screened asymptomatic schoolchildren, three reports of microscopic IH detected by case-finding, and five surveys of kidney biopsies in referred children with microscopic and gross IH. We listed the reported underlying disorders, and estimated the benefit from their early detection and treatment. Most children with microscopic IH, whether detected by screening or case-finding, had no significant underlying disease. Some had disorders that may benefit from early treatment (membranoproliferative glomerulonephritis, obstructive uropathy, urolithiasis), or counselling (hereditary nephropathy, renal cystic disease). The combined prevalence of these five diseases was 0-7.2% in children with microscopic IH detected by screening, and 3.3%-13.6% in those with microscopic IH detected by case-finding. The combined prevalence of membranoproliferative glomerulonephritis and hereditary nephropathy among kidney biopsies was 11.6%-31.6% in children with microscopic IH, and 3.6%-42.1% in children with gross IH. Variable management strategies for schoolchildren with IH result from uncertainty about the frequency of underlying disorders and the efficacy of their early treatment. With no evidence that detecting IH leads to prevention of renal function impairment, screening for IH in symptomless schoolchildren is not warranted. Once detected, however, IH justifies further investigation.

[Communication with intubated patients]

For critically ill patients on assisted respiration caring behavior is particularly important. In this paper we review the literature on patient satisfaction with medical care and with their communication with the nursing staff. Communication skills of staff of intensive respiratory care units were studied by direct observation, debriefing of hospitalized patients and by interview of discharged patients. Direct observation showed that nurses spent only a small proportion of their time talking to patients. The interactions dealt with technical rather than emotional matters and consisted mostly of negative and discouraging comments rather than positive and supporting messages. Debriefing of hospitalized intubated patients revealed a high degree of overall satisfaction with care on the one hand, and complaints of communication problems, anxiety and anger on the other. Lastly, interviews with discharged patients revealed that as many as a quarter of those who could remember their hospitalization reported feelings of anxiety, anger, distrust in the staff and difficulty in communication. These findings suggest that the nursing staff needs improved communication skills. There is evidence that the judicious use of communication techniques may improve patient satisfaction, reduce anxiety and reduce duration of treatment.

[Paradigmatic shifts in clinical practice in the the last generation]

Physicians have always used theoretical models (paradigms) to interpret clinical reality, and have changed the prevailing model only when it could no longer satisfy clinical needs. The purpose of this essay is to review some of the paradigmatic changes in clinical reasoning that have occurred since my undergraduate medial education. My training in the 50's was along the bio-medical model that reduced all diseases to structural or biochemical dysfunctions. Within this framework, causes were perceived as leading inevitably rather than probabilistically to their consequences, and chance and ambiguity had a very small role in explication of pathophysiologic mechanisms and in diagnostic reasoning. The doctor-patient relationship was paternalistic and the orientation to extending survival rejected notions of quality of life and involved parsimonious utilization of health care resources. Today however, clinical reasoning has shifted from deductive and deterministic to inductive (evidence-based) and probabilistic. Disease is believed to result from multiple factors rather than from single causes, and there is increasing acceptance of psycho-social factors of disease. Awareness of the confounding effects of false-positive and false-negative tests has changed the attitude to diagnostic evaluation. Terms, such as risk indicators of disease, predictive value of tests and risk-benefit ratio are increasingly used in discussing clinical decisions. We respect the patient's autonomy more than we did in the past, and consider his/her preferences and quality of life in clinical decision-making. Fair distribution of medical resources is considered as an ethical principle. Finally, clinical guidelines are no longer viewed as counter-intuitive, but rather as effective means to reduce the disturbingly high rates of medical error.

Teaching the social sciences to undergraduate medical students

An increasing number of medical schools have introduced undergraduate programs in the social sciences in an attempt to improve the ability of their graduates to communicate with patients and to meet their needs. However, teaching programs in the social sciences have often encountered varying degrees of student resistance, possibly because of their uncertain relevance for clinical practice, incongruity with the biomedical model, teachers' attitudes, and poorly defined educational goals. The objective of this essay is to analyze the causes of students' resistance to the social sciences and to identify the features of a teaching program responsive to their needs.

The social worker's record of the hospitalized patient: a physician's perspective

An approach to recording data related to the personality psychosocial profile of hospitalized patients is described. The approach is based on a standard format that consists of: (A) risk factors that may increase the patient's susceptibility to disease, (B) resources that may help patients cope with it, (C) extent of the patient's disability and dependence on others for his/her daily activities, and (D) the patient's and his/her family's version and understanding of the nature and prognosis of the disease. It is suggested that such a recording may influence health care by adapting the management of the patient to his/her concerns, life situation, degree of disability, additional diseases and specific needs for health promotion.

[Patient involvement in medical care]

Models of doctor-patient relationship may be broadly classified as "paternalistic"(doctor decides, patient complies) and "shared decisions" (doctor informs patient and considers patient's preferences). During recent decades there has been increasing emphasis on respect for the patient's autonomy. Physicians agree that clinical decisions require understanding of how patients view alternative treatment outcomes, and that when they can and wish to do so, patients should participate in the choice of management options. However, involving patients in medical decisions is difficult. Although population surveys have indicated an almost unanimous rejection of the paternalistic model, they have not yielded consistent results on the proportion of patients who want to participate in decision making, and of those who would prefer information and guidance, with a view to following the doctor's advice. A second difficulty relates to method: how should the various options be explained to those who want to participate in decision making? Framing, order of presentation of data and amount of data to be presented have all been shown to affect the way patients perceive aand respond to probabilistic information on treatment outcome. Therefore, there is considerable doubt regarding the applicability of the shared decision model in an unselected patient population. Further research will hopefully identify ways to elicit patient preferences and to communicate information about treatment outcomes, such as life expectancy, morbidity, burdens of taking medication and economic costs. For the present, there seems to be no substitute for the compassionate physician who treats patients with respect and who tries to understand their needs.

Inaccuracies in estimates of life expectancies of patients with bronchial cancer in clinical decision making

Approximations of life expectancy in clinical decision making frequently assume constant disease-specific ("excess") mortality hazards over age at diagnosis and over time from diagnosis. This assumption is inconsistent with the longer relative survival of younger patients with bladder cancer and with the declines in mortality hazards from bladder and breast cancers over time from diagnosis. To estimate the error that may result from these assumptions, the authors derived excess mortality hazards from the Surveillance, Epidemiology and End Result (SEER) tumor registry for bronchial cancers stratified by age at diagnosis and time from diagnosis. They compared the life expectancies calculated by a model using an average constant annual cancer-specific mortality hazard over time from diagnosis with those calculated using data-derived cancer-specific annual mortality hazards that varied as a function of time from diagnosis. For younger patients with less advanced disease, the constant-average-mortality model underestimated life expectancies by up to 50% relative to those predicted by the time-variant model. For those over 75 years old at diagnosis, and for all patients with advanced disease, the constant-average-mortality model overestimated life expectancies by up to 65% relative to those predicted by the time-variant model. The authors conclude that predictions of life expectancy with bronchial cancer, and probably with other neoplasms, are limited by the widespread use of oversimplified methods of calculation and by the lack of data describing mortality hazards as a function of time from diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Envenomation by Echis coloratus (Mid-East saw-scaled viper): a review of the literature and indications for treatment

Envenomation by the snake Echis coloratus causes a local swelling and hemostatic failure. Most cases recover uneventfully, however about one-third of the victims bleed or develop anemia, and one known death due to renal failure has been reported. Uncontrolled observations suggest that treatment by a specific antivenom reduces the duration of the hemostatic failure. Still the management of victims of E coloratus remains uncertain. Some authors advocate antivenom treatment for all patients, while others recommend its use only in the event of complications. We review reported data on the effect of the venom in vitro, in laboratory animals and in humans, and reexamine alternative treatment strategies by applying a revised version of a published decision model. The probability of bleeding and the efficacy of antivenom treatment were the main determinants in the choice between antivenom treatment and expectant management of victims of E. coloratus. Assuming a therapeutic efficacy of 32%, the decision model favored antivenom treatment when the risk of bleeding exceeded 7.5%. The estimated risk of bleeding exceeds this threshold in patients who present with either proteinuria, a blood urea of > 7 mmol/l, a platelet count of < 100,000/microliters, or a hemoglobin level of < 13 g/dl. In patients who had been exposed to antiserum in the past, or in whom the annual probability of future envenomation exceeds 0.9%, antivenom treatment was preferred only when bleeding was certain. Errors in our estimates of the efficacy of antivenom treatment, of the mortality after a bleeding event and of the risk of anaphylaxis after a repeated exposure to antiserum may have affected our conclusions. Nonetheless, they are consistent with presently available information and, pending more reliable estimates, may be considered as guidelines for treatment.

Quality of care in decentralized primary care clinics: a conceptual framework

In an attempt to provide high quality medical care, despite limited resources, health care providers in various countries have introduced decentralization into their health care services. It has been assumed that the delegation of authority to the local levels of the organization will enhance their ability to respond to local needs, and improve cost containment without compromising the quality of care. However, to date, few empirical studies have explored the relationship between decentralization and such projected outcomes. In this article we present a conceptual framework for analyzing possible consequences of decentralization on dimensions of quality of primary health care. We also suggest a framework for defining decentralization programs by their key components, and employ these frameworks to analyze a specific decentralization program being implemented in Israel's largest health maintenance organization (HMO). While we identify the dimensions most likely to be affected, we also conclude that data presently available do not permit a definitive prediction of whether the overall effect of decentralization on quality of care will be positive or negative. The potential reaction of a unit to the elements of change introduced by a decentralization program is influenced by the structural, cultural and management characteristics of that unit. Therefore, future attempts to decentralize health care organizations should be accompanied by close monitoring.

The value of urinary red cell shape in the diagnosis of glomerular and post-glomerular haematuria. A meta-analysis

The proportion of dysmorphic red cells (DRC) in the urinary sediment and their mean corpuscular volume (MCV) have been claimed to discriminate between glomerular and postglomerular sources of haematuria. To determine the diagnostic value of urinary DRC and MCV, we searched the literature and critically reviewed 21 published studies using a predetermined set of criteria for evaluation. All studies originated from referral centres. Interobserver variability in identifying urinary DRC was reported in four studies and found to be unacceptably large in one. Although reproducible over different samples of the same individual, urinary MCV was unreliable in cases of low-grade haematuria because of interfering debris. Weighted averages and 95% confidence limits of the sensitivity and specificity of the DRC proportion for glomerular disease were 0.88 (0.86-0.90) and 0.95 (0.93-0.97), respectively; those of a low MCV were 1.00 (0.98-1.00) for sensitivity and 0.87 (0.80-0.91) for specificity. Sensitivity and specificity values derived from in-patients were slightly higher than those in referred outpatients. No studies of urinary DRC or MCV in patients with incidentally detected microhaematuria in the primary care setting were found. We conclude that at present the diagnostic value of urinary DRC and MCV is limited. In referral centres, that is, in patients with a high probability of postglomerular haematuria, the test cannot rule out urological lesions, because its specificity for glomerular disease may be as low as 0.80. In the primary care setting, that is, in unselected patients with incidentally detected low-grade haematuria, the accuracy of the test has not been studied but may be even lower. The use of urinary DRC or MCV as an indicator of the source of haematuria is in need of further experimental development and confirmation.

Risk indicators after envenomation in humans by Echis coloratus (mid-east saw scaled viper)

To determine the frequency, severity and predictors of bleeding and azotemia after envenomation in humans by Echis coloratus, a retrospective survey of 68 cases in Israel between 1970 and 1989 was carried out. We used univariate and multivariate analyses of clinical variables on admission for the outcome variables of bleeding, hemoglobin and platelet levels, and blood urea. Within hours or days after envenomation, a major bleeding episode occurred in 18% of the victims, a drop in hemoglobin to 10 g/dliter or less in 14%, and an increase in blood urea to 9 mmole/liter or more in 15%. These complications correlated with time interval between envenomation and hospital admission, and the following admission variables: degree of bleeding, hemoglobin level, platelet and white blood cell counts, blood urea and proteinuria. Complications were unlikely in patients who were presented with all of the following: a hemoglobin level of 13 g/dliter or more, a platelet count of 100,000/mm3 or more, a blood urea level of 7 mmole/liter or less, no proteinuria and no bleeding. Treatment on admission with a specific monovalent antiserum was associated with a shorter duration of hemostatic failure and a reduced incidence of anemia and thrombopenia. Infusion of fresh frozen plasma on admission did not appear to be effective in preventing complications.

Factors associated with leukocyturia in asymptomatic pilots

We attempted to relate the prevalence of leukocyturia during annual examinations to recent activities and history data in 923 pilots. Urinary analysis was done and the results cross-tabulated with answers from a questionnaire and with a past history of leukocyturia obtained from the pilot's chart. The prevalence of 4 to 6 or more white blood cells (WBCs) in the urinary sediment was 5.3%. Leukocyturia was 35.7 times more common (odds ratio) in those with a previous history of leukocyturia and a concomitant history of urethritis (p less than 0.0001). Yet, a history of leukocyturia accounted for only 18.1% of the cases of leukocyturia. There was a trend for an association between jogging and leukocyturia. The prevalence of leukocyturia was not affected by smoking, other physical exercise, a history of nephrolithiasis, air duty in the preceding 24 h or a history of transient illness during the last 2 weeks. We conclude that there is an association between a history of both leukocyturia and urethritis and leukocyturia. In most cases, however none of the variables tested were found to be associated with leukocyturia.

Can decision analysis help in the management of giant hemangioma of the liver?

We explore the trade-off between the risk and expected benefits from resection of giant liver hemangioma (GLH), one larger than 4 cm in diameter. We searched the English-language literature for studies of the postoperative mortality after resection of GLH and of the outcome of expectantly treated patients. The results of the data synthesis showed an operative mortality of 1.5% (90% confidence intervals, 0.1-3.0%) and an early surgical morbidity of up to 13%. Mortality among the 37 reported cases with ruptured GLH was 78%. There were no cases of spontaneous or traumatic rupture of unresected GLH during a follow-up of a total of 282 patient years. The main source of ambiguity regarding the management of GLH is the uncertain risk of its rupture. Rough estimates of this risk based on published data suggest that surgical resection is not justified in asymptomatic GLH. Yet, although rare, rupture of GLH does occur with disastrous consequences. Future research may attempt to define patient subsets whose GLHs are at higher risk of rupture, and in whom preventive resection may improve survival.

Risk of gastric cancer after gastric surgery for benign disorders

The objective of this review was to evaluate published evidence for the association between gastric resection for benign disorders and subsequent cancer of the gastric remnant. We searched the literature through Medline (1970 to 1988) and through the references of relevant articles. Fifty-eight studies consisting of case series, uncontrolled surveys, and case control or cohort analyses were identified and critically assessed using defined methodological criteria. There were no consistent differences between the expected and observed number of cancers occurring within 15 years after gastric resection. However, all case control studies and seven of the eight cohort analyses, in which the prevalence of cancer was stratified by time since gastric resection, indicated a twofold to fourfold increase in the risk of gastric cancer in patients who survived 15 or more years after gastric surgery. We conclude that most studies of the association of gastric surgery with subsequent gastric cancer have relatively weak designs. Still, the repetitive demonstration of this association by different investigators using different research designs supports the hypothesis that gastric resection increases the risk of cancer in the gastric remnant.