An index of symptoms for infection with human immunodeficiency virus: reliability and validity

The objective of this study was to evaluate the reliability and validity of a brief index to measure symptoms in individuals infected with human immunodeficiency virus (HIV). From an ambulatory clinic that specializes in the care of HIV-infected individuals at a university hospital in northeast Ohio, 148 randomly selected outpatients (predominantly homosexual men) with a broad spectrum of HIV disease were enrolled in a prospective, cohort study. In standard interviews, patients rated the frequency of 36 symptoms related to HIV infection on an ordinal scale from zero (never) to three (daily); these interviews were repeated and outcomes determined every 3 months for one year. Clinical data were abstracted from the medical record with a standard chart review. Using specific criteria, 12 symptoms were selected for the HIV Symptom Index: fatigue, fevers, headache, imbalance, paresthesias, memory loss, cough, nausea, diarrhea, sadness, sleep disturbance, and skin problems. The HIV Symptom score (the sum of frequency ratings for the 12 symptoms) ranged from 0 to 31 with a mean of 9.4 (+/- SD 6.6). The test-retest reliability was high (intraclass correlation coefficient = 0.92) as was the internal consistency (Cronbach's alpha = 0.79). The validity of the index was established with three observations. (1) The HIV Symptom Index makes clinical sense and includes a representative spectrum of symptoms of infection. (2) Symptom Index scores were greater in patients with more advanced disease and in patients who were functionally impaired. (3) The Index was responsive to changes in health as the disease progressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Physicians' behavior and their interactions with drug companies. A controlled study of physicians who requested additions to a hospital drug formulary

OBJECTIVE

It is controversial whether physicians' interactions with drug companies affect their behavior. To test the null hypothesis, that such interactions are not associated with physician behavior, we studied one behavior: requesting that a drug be added to a hospital formulary.

DESIGN

Nested case-control study.

SETTING

University hospital.

PARTICIPANTS

Full-time attending physicians. Case physicians were all 40 physicians who requested a formulary addition from January 1989 through October 1990. Control physicians were 80 randomly selected physicians who had not made requests.

MAIN EXPOSURE MEASURE

Physician interactions with drug companies, as determined by survey of physicians (response rate, 88% [105/120]).

RESULTS

Physicians who had requested that drugs be added to the formulary interacted with drug companies more often than other physicians; for example, they were more likely to have accepted money from companies to attend or speak at educational symposia or to perform research (odds ratio [OR], 5.1; 95% confidence interval [CI], 2.0 to 13.2). Furthermore, physicians were more likely than other physicians to have requested that drugs manufactured by specific companies be added to the formulary if they had met with pharmaceutical representatives from those companies (OR, 13.2; 95% CI, 4.8 to 36.3) or had accepted money from those companies (OR, 19.2; 95% CI, 2.3 to 156.9). These associations were consistent in multivariable analyses controlling for potentially confounding factors. Moreover, physicians were more likely to have requested formulary additions made by the companies whose pharmaceutical representatives they had met (OR, 4.9; 95% CI, 3.2 to 7.4) or from whom they had accepted money (OR, 1.7; 95% CI, 1.0 to 2.7) than they were to have requested drugs made by other companies.

CONCLUSION

Requests by physicians that drugs be added to a hospital formulary were strongly and specifically associated with the physicians' interactions with the companies manufacturing the drugs.

Evaluation of a treatment limitation policy with a specific treatment-limiting order page

BACKGROUND

Concerns about misinterpretation, misunderstanding, poor communication, and lack of documentation prompted a revision of our hospital's treatment limitation policy. The revised policy was designed to explicate do-not-resuscitate (DNR) orders, structure the use of DNR and other treatment-limiting orders in a logical and standard way, and improve communication. Use of a Specific Treatment-Limiting Order Page (STOP) was required.

METHODS

To evaluate the policy's effects, we conducted (1) a prospective cohort study (involving 2733 patients) of treatment limitation practices before and after the new policy and (2) cross-sectional surveys of 58 nurses and 62 physicians. Outcome measures included documented treatment-limiting orders, documented discussions of these decisions, and deaths. Staff opinions about effects on communication and patient care were elicited.

RESULTS

Rates of death (5.4% before and 5.6% after the policy; P = .80) and rates of DNR orders (9.3% vs 9.2%, P = .9) did not change. The use of the STOP enhanced the clarity of DNR orders and, among DNR patients, greatly increased the frequency of orders limiting 12 other specific treatments for conditions short of arrest. For example, before the policy, orders prohibited mechanical ventilation in 2% of DNR patients, compared with 66% after the policy (P < .001). Staff reported that the policy improved communication among health professionals, patients, and families.

CONCLUSIONS

The treatment limitation policy with the STOP improved documentation and communication of treatment-limiting decisions. On the basis of our results, we offer a STOP for use and evaluation by others.

Developing guidelines for local use: algorithms for cost-efficient outpatient management of cardiovascular disorders in a VA Medical Center

Local use of practice guidelines requires paying close attention to the concerns of the patient within the framework of society, to the professional and educational needs of the provider, and to the realities of cost. One Veterans Affairs facility took the challenge of balancing these factors and developed their own algorithms for three cardiovascular disorders.

Anticoagulant-related bleeding: clinical epidemiology, prediction, and prevention

OBJECTIVE

To review (1) the clinical epidemiology of bleeding during anticoagulant therapy with heparin or warfarin, (2) data useful in estimating the risk for bleeding in individual patients, and (3) the efficacy of methods for its prevention.

METHODS

Relevant literature was identified by a computerized search of the Medline database and by review of the bibliographies of original and review articles. Studies were classified according to their design. Estimates of the risk for bleeding during anticoagulant therapy, compared with the risk without therapy, were obtained from randomized trials. Estimates of the frequency of bleeding during the course of anticoagulant therapy and information about risk factors for bleeding were obtained primarily from longitudinal studies of inception cohorts of patients followed from the start of therapy.

MAIN RESULTS

The average daily frequencies of fatal, major, and major or minor bleeding during heparin therapy were 0.05%, 0.8%, and 2.0%, respectively; these frequencies are approximately twice those expected without heparin therapy. The average annual frequencies of fatal, major, and major or minor bleeding during warfarin therapy were 0.6%, 3.0%, and 9.6%, respectively; these frequencies are approximately five times those expected without warfarin therapy. The risk for anticoagulant-related bleeding is highest at the start of therapy: during warfarin therapy, the risk for major bleeding during the first month of therapy is approximately 10 times the risk after the first year of therapy. An individual patient's risk for major anticoagulant-related bleeding can be estimated on the basis of specific risk factors such as the intensity of the anticoagulant effect achieved and the presence of serious comorbid diseases, especially cerebrovascular, kidney, heart, and liver disease; older age and concurrent medicines may also be independent risk factors. Major bleeding most often affects the gastrointestinal tract, soft tissues, and urinary tract. Diagnostic evaluation of gastrointestinal bleeding and gross hematuria leads to identification of previously unknown lesions in approximately one-third of cases, even when the prothrombin time is elevated. Intracranial bleeding is rare, but it is frequently fatal. The frequency of bleeding during warfarin therapy is reduced by less intense therapy achieving a prothrombin time with an International Normalized Ratio of 2.0 to 3.0, which is efficacious for most indications.

CONCLUSION

Anticoagulant-related bleeding is common and often serious. The risk for bleeding can be estimated in an individual patient, giving the primary physician a quantitative basis for weighing the risks and benefits of therapy and for optimizing patient management. The frequency of anticoagulant-related bleeding is reduced by less intense warfarin therapy. Future studies should evaluate new approaches to management that may further reduce complications while maintaining efficacy.

Rashes in immunocompromised cancer patients. The diagnostic yield of skin biopsy and its effects on therapy

BACKGROUND AND DESIGN

Rashes in immunocompromised cancer patients can be important, and skin biopsies are often recommended for their evaluation. The objectives of this study were to determine how often skin biopsy in these patients is performed and how often it alters diagnosis and therapy. Records of all immunocompromised adults with cancer and acute rash seen by dermatology consultants on a hematology-oncology ward of a university hospital for 39 months were reviewed to determine patients' course and outcome (190 episodes of rash in 123 patients).

RESULTS

Skin biopsies were performed on 108 rashes (57%); 82 rashes (43%) were evaluated without biopsy. Among the 108 patients who underwent a biopsy of their rashes, the biopsy findings supported the prebiopsy diagnosis in 51% (95% confidence interval [CI], 42% to 60%), altered it in 44% (95% CI, 35% to 53%), and did not contribute to the final diagnosis in 6% (95% CI, 2% to 12%). Fifteen of 108 biopsies (14%) (95% CI, 7% to 21%) changed systemic therapy. Most treatment changes were for cutaneous reactions to drugs; biopsy never resulted in the diagnosis of untreated systemic infection. Biopsy findings that altered diagnoses were not more likely to change therapy. Among the 82 rashes in which biopsies were not performed, review of the chart revealed no adverse sequelae (0%) (95% CI, 0% to 5%), which would have made a biopsy advisable.

CONCLUSIONS

Skin biopsy findings often changed dermatologic diagnoses in immunocompromised cancer patients, but treatment changes based on biopsy results were much less common, and altered diagnoses in patients who underwent biopsy often did not change therapy. Untreated systemic infection was never diagnosed by means of a skin biopsy. Skin biopsies of these rashes may not be mandatory for either diagnostic or therapeutic reasons.

Do older Medicare patients cost hospitals more? Evidence from an academic medical center

BACKGROUND

It is uncertain, under prospective payment, if hospitals face financial disincentives to treat older Medicare patients. Therefore, we studied associations between age and hospital charges and length of stay for Medicare patients and the impact on hospital reimbursement of Medicare's decision in October 1987 to eliminate older age (> or = 70 years) as a criterion for stratifying diagnosis-related groups (DRGs).

METHODS

The 23,179 medical and surgical admissions to one academic medical center in 1985 through 1989 who were aged 65 years or more were studied using a retrospective cohort design. Clinical and financial data were obtained from hospital databases; charges and length of stay for each patient were adjusted for DRG weight, the measure used to determine reimbursement. Admission severity of illness was measured for 11,060 patients using the Nursing Severity Index, a previously validated method.

RESULTS

Compared with patients aged 65 to 69 years, DRG-adjusted charges were 1%, 5%, 5%, and 6% higher and DRG-adjusted length of stay was 4%, 11%, 16%, and 18% greater for patients aged 70 to 74 years, 75 to 79 years, 80 to 84 years and 85 years or more, respectively. In multivariate analyses, these estimates were similar, even after controlling for sex, race, socioeconomic status, and other variables associated with charges and length of stay. However, further controlling for severity of illness revealed that nearly all of the differences in charges and a large proportion of the differences in length of stay in older patients could be explained by their higher severity of illness. In separate stratified analyses, the association with age was stronger and more consistent in patients admitted after October 1987 and in medical patients.

CONCLUSIONS

These findings suggest that currently hospitals may face financial disincentives to care for older Medicare patients and that the equitability of DRG-based hospital payments, with respect to age, may have been adversely affected by Medicare's decision to eliminate older age (> or = 70 years) as a criterion for classifying DRGs. The inclusion of patient age in prospective payment formulas may make hospital reimbursement more equitable.

Development and validation of the Nursing Severity Index. A new method for measuring severity of illness using nursing diagnoses. Nurses of University Hospitals of Cleveland

The purpose of this study was to develop and validate the Nursing Severity Index, a new method used to measure the admission severity of illness of hospital patients using nursing diagnoses, which categorize biologic, functional, cognitive, and psychosocial abnormalities. This retrospective cohort study with independent development and testing phases was conducted at a U.S. academic medical center. In the development phase, data regarding 14,183 adult medical-surgical patients admitted to the medical center in 1985 and 1986 was used. In the testing phase, data regarding 7,302 patients admitted in 1987 and 1988 was used. Primary nurses prospectively recorded the presence or absence of 61 nursing diagnoses on admission. Demographic and clinical data were obtained from hospital data bases. In the development phase, the number of admission nursing diagnoses was highly related (P < 0.001) to in-hospital mortality. Using multiple logistic regression, 34 nursing diagnoses were identified as independent predictors of mortality; the Nursing Severity Index equals the number of these 34 diagnoses. In the testing phase of 7,302 patients, the Nursing Severity Index was related (P < 0.001) to mortality rates, which were 0.5%, 1%, 2%, 6%, 13%, 22%, and 31% in seven hierarchical strata defined by the Index. The Index was as accurate in predicting mortality as MedisGroups (receiver-operating-characteristic curve areas, 0.814 +/- 0.016 vs. 0.845 +/- 0.015, respectively, P = 0.12). Furthermore, the Nursing Severity Index and MedisGroups together (receiver operating characteristic curve area 0.880 +/- 0.014), were more accurate (P < 0.01) than either measure alone. The Nursing Severity Index assesses multiple dimensions of illness, can be easily measured during routine patient care, accurately predicts the risk of in-hospital death, and has similar prognostic accuracy as MedisGroups. Its usefulness in outcomes assessment, quality assurance, and case management merits further study.

Sexual behavior, knowledge, and attitudes about AIDS among college freshmen

We surveyed 158 college freshmen on an urban campus to determine their sexual practices and their knowledge and attitudes about acquired immunodeficiency syndrome (AIDS). Many students (47%) were heterosexually active; 1% were homosexual, 1% were bisexual, and 51% had not been sexually active. Among the 77 sexually active students, many engaged in activities that can facilitate transmission of human immunodeficiency virus (HIV): 58% did not always use condoms with a new partner; 31% had had two or more sex partners in the last year; 8% engaged in anonymous sex; and 14% of sexually active women had anal intercourse. Although most sexually active students said they would use condoms more or reduce the number of their sexual partners if they believed these changes would reduce "my risk for getting AIDS," few students had adopted these safer sexual practices. Safer sexual practices were associated with heightened personal concerns about AIDS but not with knowledge, which was at a high level. These findings underscore the need for preventive programs that overcome the gap between knowledge and safer sexual behaviors in this and similar groups of adolescents and suggest that programs that heighten personal concerns may be most effective. Community-based physicians who care for adolescents should develop such preventive programs and integrate them into their practices.

Guideline-based consultation to prevent anticoagulant-related bleeding. A randomized, controlled trial in a teaching hospital

OBJECTIVE

To test the efficacy of consultation designed to prevent anticoagulant-related bleeding.

DESIGN

Randomized, controlled trial.

SETTING

A large teaching hospital.

PATIENTS

A total of 101 patients at increased (greater than 15%) risk for major, in-hospital bleeding while starting long-term anticoagulant therapy who were identified using a validated prediction rule.

INTERVENTIONS

Fifty-five patients received usual care under the direction of the attending physician who had initiated anticoagulant therapy. Forty-six patients received guideline-based consultation in addition to usual care. Guideline-based consultation included individualized review of the risks and benefits of anticoagulant therapy and, on the basis of current practice guidelines, recommendations for daily management.

MEASUREMENTS

The main outcome was in-hospital bleeding, which was classified using a reliable, explicit index.

RESULTS

Major or minor bleeding occurred in 17 of 55 patients (31%) receiving usual care alone, compared with 6 of 46 patients (13%) receiving consultation in addition to usual care (P = 0.03). The protective efficacy of consultation was 58% (95% CI, 3% to 82%). Consultation was associated with similar reductions in the frequencies of major bleeding (from 13% to 4%) and minor bleeding (from 18% to 9%). Consultative recommendations had an 84% compliance rate and directly affected anticoagulant management: In the consult group, nonsteroidal anti-inflammatory agents were stopped in six patients (13%), and therapeutic ranges were achieved more often for activated partial thromboplastin times (52% compared with 45% in the usual care group, P = 0.08) and for prothrombin times (47% compared with 27% in the usual care group, P less than 0.001). Nearly all housestaff and attending physicians (91%) for patients receiving consultation also reported that consultation improved housestaff learning. The consult group had a somewhat lower rate of thromboembolism in the 90 days after discharge (5% compared with 17%, P = 0.06). Death rates and mean lengths of stay were similar in the two groups.

CONCLUSION

Guideline-based consultation was associated with reduction in the frequency of anticoagulant-related bleeding in patients at increased risk for major in-hospital bleeding.

Diagnostic judgments of nurse practitioners providing primary gynecologic care: a quantitative analysis

OBJECTIVES

To determine the accuracy of experienced nurse practitioners' judgments of the probability of chlamydial infection of the cervix, to identify the clinical factors ("cues") related to the judgments, and to discern likely sources of judgment error.

DESIGN

Cross-sectional study with prospective data collection.

SETTING

Urban hospital-based clinic.

PATIENTS

492 nonpregnant women receiving primary gynecologic care.

INTERVENTIONS

Four nurse practitioners recorded clinical data, tested women for chlamydial infection, and judged the probability of chlamydial infection using six categories: less than 1%, 1-4%, 5-9%, 10-24%, 25-50%, and greater than 50%.

MEASUREMENTS AND MAIN RESULTS

Chlamydial infection was detected by immunofluorescent assay in 31 (6%) of the 492 women. Although the median probability judgment was 5-9%, judgments were only weakly related (p = 0.08) to actual rates of infection. In a multivariate analysis, eight clinical cues were independently (p less than 0.05) related to nurse practitioners' probability judgments: age less than 20 years; past chlamydial or gonococcal infection; new sex partner; partner with suspected genital infection; genito-urinary symptoms; cervicitis, purulent vaginal discharge; and malodorous vaginal discharge. A linear model based on the eight cues, weighted according to their regression coefficients, predicted chlamydial infection more accurately than did the nurse practitioners' actual judgments (ROC curve areas 0.69 vs. 0.58, respectively; p less than 0.05). However, only two of the eight cues (age less than 20 years and purulent vaginal discharge) were actually related to chlamydial infection in a second multivariate model; this model bad accuracy similar to that of an empirically derived prediction rule (ROC curve areas 0.77 and 0.80, p = 0.27).

CONCLUSIONS

Nurse practitioners were often inaccurate in their diagnostic judgments. Our analyses suggest that this inaccuracy stemmed from both the inconsistent use of clinical cues and the use of cues that were not related to chlamydial infection. Therefore, interventions such as algorithms that promote consistency and accuracy in diagnostic use of relevant cues would be likely to improve their diagnostic judgments.

The Cleveland Veterans Affairs Medical Center firm system

Hospital-based "firms" provide a means for combatting the fragmentation experienced by both patients and caregivers in the modern teaching hospital environment. A "firm" is an academic group practice that includes attending physicians, physician trainees, nurses, other staff, and patients. Each person's relationship with a firm lasts throughout his or her association with a particular institution. This article describes the firm system that was recently implemented on the Medical Service of the Cleveland VAMC. This system incorporates both inpatient and outpatient general medical services and provides for unbiased assignment of patients, physicians, and nurses.

Doctors, drug companies and gifts

This paper by Chren and Landefeld was originally presented at the Miriam Hospital on March 21, 1991, as the 1991 Lichtman Oration, an annual meeting devoted to ethical problems in medicine honoring Herbert C. Lichtman, MD, former physician-in-chief at the hospital. Because of the importance of this paper, and its controversial character, the Journal has asked a number of practicing physicians and other concerned persons to offer their opinions on this paper. These commentaries will then be published in a subsequent issue of the Journal, along with reactions by our readers.

Failure to limit quantities of benzodiazepine hypnotic drugs for outpatients: placing the elderly at risk

PURPOSE

The long-term use of benzodiazepine hypnotics by the elderly is associated with serious side effects, and prescriptions of large quantities of these agents allow such use. Therefore, we determined the quantities of these agents prescribed to outpatients in our Veterans Administration teaching hospital, and the relationship of patient age to total number of doses prescribed per prescription.

PATIENTS AND METHODS

Pharmacy and patient records related to 655 consecutive prescriptions for triazolam (Halcion) and flurazepam (Dalmane) were reviewed. Only 266 (41%) of the prescriptions were for 30 or fewer doses, while 178 (27%) were written for 180 or more doses.

RESULTS

Thirty-six percent of prescriptions for patients aged 65 years or older were for 180 or more doses, compared with 24% for those aged 45 to 64 years old, and 16% of the prescriptions for patients less than 45 years old (p less than 0.0001). In a multivariate analysis controlling for six other factors related to the total number of doses prescribed, patients aged 65 years or older were still more likely to receive a prescription for 180 or more doses (relative risk 1.9, 95% confidence interval 1.3, 2.8).

CONCLUSION

We conclude that inappropriately large quantities of benzodiazepine hypnotics were commonly prescribed, and that patients aged 65 years or older were at greatest risk for receiving such prescriptions.

A bleeding risk index for estimating the probability of major bleeding in hospitalized patients starting anticoagulant therapy

PURPOSE

To construct and test prospectively a bleeding risk index for estimating the probability of major bleeding in hospitalized patients starting long-term anticoagulant therapy.

PATIENTS AND METHODS

In an inception cohort of 617 patients starting long-term anticoagulant therapy in one hospital, data were gathered retrospectively and bleeding was classified using reliable explicit criteria. We constructed a bleeding risk index by identifying and weighting independent predictors of major bleeding using a multivariate proportional-hazards model. The bleeding risk index was tested in 394 other patients prospectively identified in a second hospital. The index was compared to physicians' predictions.

RESULTS

Major bleeding developed before discharge in 61 of all 1,011 patients (6%). The bleeding risk index included four independent risk factors for major in-hospital bleeding: the number of specific comorbid conditions; heparin use in patients aged 60 years or older; maximal prothrombin or partial thromboplastin time 2.0 or more times control; liver dysfunction worsening during therapy. In the testing group, the index predicted major bleeding, which occurred in 3% of 235 low-risk patients, 16% of 96 middle-risk patients, and 19% of 63 high-risk patients (p less than 0.001). The bleeding risk index performed as well as physicians' predictions, and integration of the bleeding risk index with physicians' predictions led to a classification system that was more sensitive (p = 0.03) than physicians' predictions alone. In 86% of patients with a high risk of major bleeding, we identified specific ways of improving therapy, e.g., avoiding overanticoagulation and nonsteroidal anti-inflammatory agents.

CONCLUSION

The bleeding risk index provides valid estimates of the probability of major bleeding in hospitalized patients starting long-term anticoagulant therapy and complements physicians' predictions. The possibility that bleeding can be prevented in high-risk patients warrants prospective evaluation.

A new diagnostic index for predicting cervical infection with either Chlamydia trachomatis or Neisseria gonorrhoeae

OBJECTIVE

To develop and test a diagnostic index for estimating the probability of cervical infection with either Chlamydia trachomatis or Neisseria gonorrhoeae.

DESIGN

Prospective, cross-sectional study in two phases: 1) to develop a diagnostic index based on independent predictors of cervical infection; 2) to test the index.

SETTINGS

A hospital-based clinic and a student health service.

PATIENTS

Development phase: 190 nonpregnant women seen in the gynecology clinic; testing phase: 588 women seen in the gynecology clinic (n = 372) or the student health service (n = 216).

INTERVENTIONS

Experienced clinicians recorded historical, physical, and microscopic findings on standard forms and tested women for chlamydial and gonococcal infections.

RESULTS

Three independent predictors of cervical infection were identified and weighted: age (two points if less than 20 years and one point if 20-29 years); a new sex partner or one suspected of having a genital infection (one point); purulent vaginal discharge (one point). In the testing groups, cervical infection was present in none of 62 women with no points, seven of 269 (3%) with one point, 14 of 188 (7%) with two points, and 19 of 69 (28%) with three or four points (p less than 0.001). The index estimated the probability of infection more accurately (p less than 0.01) than did clinicians, performed well in each site, and remained accurate when C. trachomatis and N. gonorrhoeae were considered separately.

CONCLUSION

The diagnostic index accurately estimates the probability of cervical infection with either C. trachomatis or N. gonorrhoeae and may be useful in selecting women for definitive diagnostic testing.

Clinical findings associated with acute proximal deep vein thrombosis: a basis for quantifying clinical judgment

PURPOSE

To identify clinical findings useful in estimating the probability of acute proximal deep vein thrombosis (DVT).

PATIENTS AND METHODS

The records of 355 symptomatic patients who underwent ascending venography were reviewed. Data on 76 clinical items were collected using standardized forms. Venograms were interpreted according to standard criteria and interobserver agreement was evaluated in a sample of 119 venograms. Independent clinical correlates of proximal DVT were identified using multivariate discriminant analysis in 236 randomly chosen patients; they were tested in the remaining 119 patients.

RESULTS

Acute proximal DVT was shown by venogram in 96 patients (27%). Five independent clinical correlates of proximal DVT--swelling above the knee of the affected leg, swelling below the knee, recent immobility, cancer, fever--predicted proximal DVT in the testing group; in patients with none, one, or two or more of these clinical findings, proximal DVT was present in 5%, 15%, and 42%, respectively. If venography had been performed only in patients with one or more of the five factors, 97% of cases of proximal DVT would have been diagnosed and venography would have been avoided in 26% of patients with normal test results.

CONCLUSION

These data provide a quantitative basis for estimating the probability of proximal DVT on the basis of clinical findings in symptomatic patients. How these findings can best be integrated with noninvasive testing and venography into diagnostic strategies for DVT remains to be determined.

The relation of chlamydial infection of the cervix to time elapsed from the onset of menses

To investigate the relation of chlamydial infection of the cervix to time elapsed from the onset of menses, we prospectively studied 338 women receiving routine gynecologic care in two clinical sites in which the prevalence of chlamydial infection was 3 and 6%. Eleven (13%) of 86 women evaluated in the fourth or fifth week after the onset of menses (days 22-35) had chlamydial infection compared to 4 (1.6%) of 252 women seen in the first 3 weeks (days 1-21) (p less than 0.001). For women seen in the fourth or fifth week, the relative risk of chlamydial infection was 8.1 (95% CI, 3.1-20.6). Controlling for known risk factors for chlamydial infection with multiple logistic regression analysis, the relative risk was sustained (RR 10.8; 95% CI, 3.1-37.4). We conclude that time elapsed from the onset of menses is an important independent risk factor for chlamydial infection of the cervix that may lead to more effective and efficient screening strategies.

Doctors, drug companies, and gifts

Doctors often accept gifts from drug companies. We analyze this practice and conclude that accepting a gift has complex practical and ethical repercussions. Gifts cost patients money, and they may change society's perception of the profession as serving the best interest of patients. Also, accepting a gift establishes a relationship between the physician and the drug company that obliges a response from the physician. Accepting gifts and the resulting relationship have ethical implications as well. First, the use of patients' money to pay for gifts can be unjust. Second, the fiduciary relationship between physician and patient may be threatened if prescribing practices are affected (as intended by the drug company). Third, physicians' characters may be altered by a practice that fosters self-interest at patients' expense. We discuss the need for guidelines for the profession to help physicians promote their patients' well-being.

Major bleeding in outpatients treated with warfarin: incidence and prediction by factors known at the start of outpatient therapy

PURPOSE

To determine the incidence of major bleeding in outpatients treated with warfarin and to identify predictive factors known at the start of therapy.

PATIENTS AND METHODS

The records of 565 patients starting outpatient therapy with warfarin upon discharge from a university hospital were reviewed. Follow-up information was obtained for 562 patients (99.5%). Bleeding was classified as major or minor using explicit criteria. The cumulative incidence of bleeding was estimated by means of survival analysis. Independent risk factors for major bleeding were identified using Cox regression analysis in 375 randomly chosen patients; they were tested in the remaining 187 patients.

RESULTS

Major bleeding occurred in 65 patients (12%) and was fatal in 10 patients (2%). The cumulative incidences of major bleeding at one, 12, and 48 months were 3%, 11%, and 22%, respectively. The monthly risk of major bleeding decreased over time, from 3% during the first month of outpatient therapy to 0.3% per month after the first year of therapy. Five independent risk factors for major bleeding--age 65 years or greater, history of stroke, history of gastrointestinal bleeding, a serious comorbid condition (recent myocardial infarction, renal insufficiency, or severe anemia), atrial fibrillation--predicted major bleeding in the testing group; the cumulative incidence of major bleeding at 48 months was 2% in 57 low-risk patients, 17% in 110 middle-risk patients, and 63% in 20 high-risk patients.

CONCLUSION

These findings provide a quantitative basis for evaluating the risk of major bleeding in individual patients at the start of outpatient therapy with warfarin. Whether the risk of bleeding can be reduced in high-risk patients without reducing the benefit of therapy remains to be determined.

Bleeding in outpatients treated with warfarin: relation to the prothrombin time and important remediable lesions

PURPOSE

To determine the relation of bleeding to prothrombin times and important remediable lesions in outpatients treated with warfarin.

PATIENTS AND METHODS

An inception cohort of 565 patients starting outpatient therapy with warfarin on discharge from a university hospital was assembled. Detailed records of outpatient prothrombin times were obtained for 103 of 130 case subjects with major or minor bleeding and for 117 control patients without bleeding. A nested case-control design was used to evaluate the association of bleeding with temporally related prothrombin times; odds ratios were estimated using multivariate logistic regression analysis to control for known predictors of major bleeding. The relation of bleeding to important remediable lesions was determined in all 130 cases of bleeding.

RESULTS

For each 1.0 increase in the prothrombin time-to-control ratio, the odds ratio for major bleeding during the week after a prothrombin time measurement increased 80%; the odds ratio for minor bleeding increased 50%. These odds ratios were lower during the first month of therapy and higher thereafter. Bleeding was related to important remediable lesions in 49 of 130 cases (38%), but these lesions were unknown before bleeding in only 22 cases (17%). The mean prothrombin time rose sharply at the time of bleeding in patients without important remediable lesions, but not in patients with lesions. New, previously unknown lesions (including nine malignancies) were discovered in 20 of 59 case subjects (34%) with gastrointestinal bleeding or hematuria, but in only two of 71 case subjects (3%) with other bleeding (p less than 0.001).

CONCLUSION

Our results provide a valid quantitative basis for estimating the odds of bleeding in relation to the prothrombin time and the yield of diagnostic evaluation in patients with bleeding.