Patients who leave emergency departments without being seen by a physician: magnitude of the problem in Los Angeles County.

STUDY OBJECTIVES: To determine the hospital characteristics associated with patients leaving emergency departments prior to physician evaluation. DESIGN: Cross-sectional design with data collection by mail and telephone survey. SETTING: Los Angeles County, California. TYPE OF PARTICIPANTS: Convenience sample of four public and 26 private hospital EDs with a combined monthly volume of 92,570. INTERVENTIONS: None. RESULTS: Questionnaires were returned from 83% of EDs surveyed. During 1990, 4.2% of patients at these EDs left without being seen by a physician. In all, 7.3% of public hospital patients left without being seen, and 2.4% of private hospital patients left without being seen (P < .001). The percentage of patients who left without being seen was significantly higher at EDs with longer waiting times, higher fraction of uninsured patients, and at hospitals with accredited residency training programs (P < .001 for each comparison). A logistic regression model, used to simultaneously evaluate the effects of multiple correlated factors, revealed that waiting time, fraction of patients uninsured, and teaching status had independent positive associations with patients who left without being seen. CONCLUSION: More than 4% of patients who seek care at EDs in Los Angeles County leave without being seen by a physician. A greater proportion of patients leave without medical evaluation from EDs with long waiting times for ambulatory patients and from those that serve uninsured populations. These findings should be interpreted in light of existing data on the health consequences faced by patients who leave hospital EDs without treatment.

Detection of onco-fetal bladder antigen in urine of patients with transitional cell carcinoma.

Studies of antigens associated with transitional cell carcinoma were extended by using murine IgM monoclonal antibody E7, developed earlier by this laboratory. These antibodies react preferentially with human bladder tumors and transitional cell carcinoma (TCC) cell line 647V. We now report that monoclonal antibody E7 detected the presence of antigen in midgestational and third trimester amniotic fluids, and in urine of patients with advanced transitional cell carcinoma. Western blot analysis showed that the antigen present in amniotic fluids consists of a sharp band with molecular weight greater than 200 kdaltons. A similar molecular weight pattern was seen with the solubilized membrane of 647V. A sensitive and convenient sandwich ELISA was developed and the urine of patients with bladder cancer was assayed for the presence of the E7 antigen. Antigen was detected in the urine of patients with advanced transitional cell carcinoma but not in the urine of normal adults or in urine from patients with prostate cancer, renal cell carcinoma, or benign prostate hyperplasia. An inhibition enzyme immunoassay was developed with monomeric forms of the E7 antibody and confirmed the presence of antigen in the urine of patients with TCC. We conclude that the E7 antigen is an onco-fetal antigen expressed in patients with transitional cell carcinoma of the bladder.

Ras related oncogene protein as a tumor marker in transitional cell carcinoma of the bladder.

An oncogene related protein has been detected in the urine of patients with transitional cell carcinoma (TCC). This is a 55 kilodalton protein (p55) which is immunologically related to the ras oncogene product p21. Sixteen patients with TCC (55%) and none of the controls exhibited high level of p55 expression (greater than or equal to 3X the level of background). There were ten cancer patients (35%) who had 2X the level of background and three patients (10%) who had the level of background. In contrast, there were two non-cancer patients with 2X level of expression (9%) and the remainder (91%) had the background level of p55 expression. The expression of the marker (p55) tends to correlate with tumor grade and stage and is elevated in patients with a history of multiple recurrences. The ras oncogene has been identified in the tissues of a wide variety of cancers and is not a marker which is specific for any single cancer. The identification of its related gene product in the urine may be useful as a marker for TCC.

Development of an enzyme-linked immunosorbent assay for studying Pseudomonas aeruginosa cell surface antigens.

An enzyme-linked immunosorbent assay for the measurement of antibodies directed against Pseudomonas aeruginosa cell surface antigens was developed. Formalin-killed whole cells of P. aeruginosa, adsorbed to polystyrene acrylic copolymer cuvettes, were used as immobilized antigens. Antisera to P. aeruginosa mucoid strain 144M and to its spontaneous nonmucoid derivative, 144NM, were raised in rabbits by immunization with Formalin-killed bacteria. By using this enzyme-linked immunosorbent assay, anti-144M serum was found to have a ca. 10-fold-higher antibody titer to 144M than did anti-144NM serum, suggesting that 144M may have either immunogenic determinants not present on 144NM or perhaps simply more antigenic determinants. In contrast, anti-144M and anti-144NM immune sera were found to have nearly identical antibody titers to 144NM, suggesting that these strains share many determinants. Anti-P. aeruginosa immune serum was found to contain Pseudomonas-specific antibodies as well as antibodies which cross-reacted with other gram-negative bacteria. Finally, absorption studies demonstrated that this assay can detect both LPS and non-LPS surface-exposed antigenic determinants. Thus, this whole bacterial cell enzyme-linked immunosorbent assay should prove useful in monitoring patient sera and secretions for potentially protective immunoglobulins directed at P. aeruginosa cell surface antigens.