Incidence of venous thromboembolism in hospitalized patients vs community residents.

OBJECTIVE: To estimate the incidence rates of deep venous thrombosis (DVT) and pulmonary embolism (PE) in hospitalized patients and to compare these with incidence rates in community residents. PATIENTS AND METHODS: We performed a retrospective review of the complete medical records from a population-based inception cohort of patients who resided in Olmsted County, Minnesota, and had an incident DVT or PE from 1980 through 1990. RESULTS: From 1980 through 1990, 911 Olmsted County residents experienced their first lifetime event of definite, probable, or possible venous thromboembolism. Of these residents, 253 had been hospitalized for some reason other than a diagnosis of DVT or PE (in-hospital cases), and 658 were not hospitalized at onset of venous thromboembolism (community residents). The average annual age- and sex-adjusted incidence of in-hospital venous thromboembolism was 960.5 (95% confidence interval, 795.1-1125.9) per 10,000 person-years and was more than 100 times greater than the incidence among community residents at 7.1 (95% confidence interval, 6.5-7.6) per 10,000 person-years. The incidence of venous thromboembolism rose markedly with increasing age for both groups, with PE accounting for most of the age-related increase among in-hospital cases. Incidence rates in the 2 groups changed little over time despite a reduction in the average length of hospital stay between 1980 and 1990. CONCLUSIONS: Venous thromboembolism is a major national health problem, especially among elderly hospitalized patients. This finding emphasizes the need for accurate identification of hospitalized patients at risk for venous thromboembolism and a better understanding of the mechanisms involved so that safe and effective prophylaxis can be implemented.

The epidemiology of venous thromboembolism in the community.

The incidence of venous thromboembolism exceeds 1 per 1000; over 200,000 new cases occur in the United States annually. Of these, 30% die within 30 days; one-fifth suffer sudden death due to pulmonary embolism. Despite improved prophylaxis, the incidence of venous thromboembolism has been constant since 1980. Independent risk factors for venous thromboembolism include increasing age, male gender, surgery, trauma, hospital or nursing home confinement, malignancy, neurologic disease with extremity paresis, central venous catheter/transvenous pacemaker, prior superficial vein thrombosis, and varicose veins; among women, risk factors include pregnancy, oral contraceptives, and hormone replacement therapy. About 30% of surviving cases develop recurrent venous thromboembolism within ten years. Independent predictors for recurrence include increasing age, obesity, malignant neoplasm, and extremity paresis. About 28% of cases develop venous stasis syndrome within 20 years. To reduce venous thromboembolism incidence, improve survival, and prevent recurrence and complications, patients with these characteristics should receive appropriate prophylaxis.

Trends in the incidence of venous stasis syndrome and venous ulcer: a 25-year population-based study.

BACKGROUND: The incidence rates of venous stasis syndrome and venous ulcer are uncertain, and trends in incidence are unknown. METHODS: We performed a retrospective review of the complete (inpatient and outpatient) medical records of a community population (Olmsted County, Minnesota) to estimate the incidence of venous stasis syndrome and venous ulcer during the 25-year period, 1966 to 1990, and to describe trends in incidence. RESULTS: A total of 1131 patients received a first lifetime diagnosis of venous stasis syndrome. A total of 263 patients received a first lifetime diagnosis of venous ulcer. The overall incidence of venous stasis syndrome and venous ulcer were 76.1 and 18.0 per 100,000 person-years, respectively. The incidence of both was higher in women than in men (83.7 vs 67.4 per 100,000 person-years for venous stasis syndrome; 20.4 vs 14.6 per 100,000 for venous ulcer) and increased with age for both sexes. There was no clear trend in the incidence of venous stasis syndrome over the 25-year period. Compared with 1966 to 1970, the incidence of venous ulcer decreased in 1971 to 1980, but was unchanged after 1981. Among 945 patients with venous stasis only, 60 subsequently had a venous ulcer. The average (+/- SD) time from venous stasis diagnosis to development of a venous ulcer was 5.0 (+/- 5.0) years. CONCLUSION: Venous stasis syndrome and venous ulcer are common, especially in the elderly population. The incidence of venous stasis syndrome has not changed since 1966, and venous ulcer incidence is unchanged since 1981. More accurate identification of patients at risk for venous stasis syndrome and venous ulcer and more effective prevention are needed.

The venous stasis syndrome after deep venous thrombosis or pulmonary embolism: a population-based study.

OBJECTIVES: To estimate the incidence and determine predictors of venous stasis syndrome and venous ulcers after deep venous thrombosis and pulmonary embolism. PATIENTS AND METHODS: This population-based retrospective cohort study reviewed medical records of 1527 patients with incident deep venous thrombosis or pulmonary embolism between 1966 and 1990. We recorded baseline characteristics, event type (deep venous thrombosis with or without pulmonary embolism or pulmonary embolism alone), leg side and site of deep venous thrombosis (proximal with or without distal deep venous thrombosis vs distal deep venous thrombosis alone), and venous stasis syndrome and venous ulcer. RESULTS: Two hundred forty-five patients developed venous stasis syndrome. One-year, 5-year, 10-year, and 20-year cumulative incidence rates were 7.3%, 14.3%, 19.7%, and 26.8%, respectively. By 20 years the cumulative incidence of venous ulcers was 3.7%. Patients with deep venous thrombosis with or without pulmonary embolism were 2.4-fold (95% confidence interval, 1.7-fold-3.2-fold) more likely to develop venous stasis syndrome than patients with pulmonary embolism and no diagnosed deep venous thrombosis. In patients aged 40 years or younger with proximal compared with distal-only deep venous thrombosis, venous stasis syndrome was 3.0-fold more likely (95% confidence interval, 1.6-fold-4.7-fold). In patients with unilateral leg deep venous thrombosis, venous stasis syndrome usually developed in the concordant leg (P < .001). There was a 30% (95% confidence interval, 2%-62%) increased risk for venous ulcer per decade of age at the incident venous thromboembolism. CONCLUSIONS: The cumulative incidence of venous stasis syndrome continues to increase for 20 years after venous thromboembolism. Pulmonary embolism alone is less likely to cause venous stasis syndrome.

The canalith repositioning procedure for the treatment of benign paroxysmal positional vertigo: a randomized controlled trial.

OBJECTIVE: To compare the canalith repositioning procedure (CRP) with a sham maneuver for the treatment of benign paroxysmal positional vertigo. PATIENTS AND METHODS: We recruited 50 patients with a history of positional vertigo and unilateral positional nystagmus on physical examination (Dix-Hallpike maneuver). Patients were randomized to either the CRP (n = 24) or a sham maneuver (n = 26). Measured outcomes included resolution of vertigo and positional nystagmus at follow-up examination. RESULTS: The mean duration of follow-up was 10 days for both groups. Resolution of symptoms was reported by 12 (50%) of the 24 patients in the CRP group and by 5 (19%) of the 26 patients in the sham group (P = .02). The results of the Dix-Hallpike maneuver were negative for positional nystagmus in 16 (67%) of 24 patients in the CRP group and in 10 (38%) of 26 patients in the sham group (P = .046). CONCLUSION: The CRP is effective treatment of benign paroxysmal positional vertigo, and this procedure can be performed by general internists on outpatients with this disorder.

Predictors of recurrence after deep vein thrombosis and pulmonary embolism: a population-based cohort study.

BACKGROUND: The appropriate duration of oral anticoagulation after a first episode of venous thromboembolism (VTE) is uncertain and depends upon VTE recurrence rates. OBJECTIVE: To estimate VTE recurrence rates and determine predictors of recurrence. METHODS: Patients in Olmsted County, Minnesota, with a first lifetime deep vein thrombosis or pulmonary embolism diagnosed during the 25-year period from 1966 through 1990 (N = 1,719) were followed forward in time through their complete medical records in the community for first VTE recurrence. RESULTS: Four hundred four patients developed recurrent VTE during 10,198 person-years of follow-up. The overall (probable/definite) cumulative percentages of VTE recurrence at 7, 30, and 180 days and 1 and 10 years were 1.6% (0.2%), 5.2% (1.4%), 10.1% (4.1%), 12.9% (5.6%), and 30.4% (17.6%), respectively. The risk of recurrence was greatest in the first 6 to 12 months after the initial event but never fell to zero. Independent predictors of first overall VTE recurrence included increasing age and body mass index, neurologic disease with paresis, malignant neoplasm, and neurosurgery during the period from 1966 through 1980. Independent predictors of first probable/definite recurrence included diagnostic certainty of the incident event and neurologic disease in patients with hospital-acquired VTE. Recurrence risk was increased by malignant neoplasm but varied with concomitant chemotherapy, patient age and sex, and study year. CONCLUSIONS: Venous thromboembolism recurs frequently, especially within the first 6 to 12 months, and continues to recur for at least 10 years after the initial VTE. Patients with VTE with neurologic disease and paresis or with malignant neoplasm are at increased risk for recurrence, while VTE patients with transient or reversible risk factors are at less risk.

Risk factors for deep vein thrombosis and pulmonary embolism: a population-based case-control study.

BACKGROUND: Reported risk factors for venous thromboembolism (VTE) vary widely, and the magnitude and independence of each are uncertain. OBJECTIVES: To identify independent risk factors for deep vein thrombosis and pulmonary embolism and to estimate the magnitude of risk for each. PATIENTS AND METHODS: We performed a population-based, nested, case-control study of 625 Olmsted County, Minnesota, patients with a first lifetime VTE diagnosed during the 15-year period from January 1, 1976, through December 31, 1990, and 625 Olmsted County patients without VTE. The 2 groups were matched on age, sex, calendar year, and medical record number. RESULTS: Independent risk factors for VTE included surgery (odds ratio [OR], 21.7; 95% confidence interval [CI], 9.4-49.9), trauma (OR, 12.7; 95% CI, 4.1-39.7), hospital or nursing home confinement (OR, 8.0; 95% CI, 4.5-14.2), malignant neoplasm with (OR, 6.5; 95% CI, 2.1-20.2) or without (OR, 4.1; 95% CI, 1.9-8.5) chemotherapy, central venous catheter or pacemaker (OR, 5.6; 95% CI, 1.6-19.6), superficial vein thrombosis (OR, 4.3; 95% CI, 1.8-10.6), and neurological disease with extremity paresis (OR, 3.0; 95% CI, 1.3-7.4). The risk associated with varicose veins diminished with age (for age 45 years: OR, 4.2; 95% CI, 1.6-11.3; for age 60 years: OR, 1.9; 95% CI, 1.0-3.6; for age 75 years: OR, 0.9; 95% CI, 0.6-1.4), while patients with liver disease had a reduced risk (OR, 0.1; 95% CI, 0.0-0.7). CONCLUSION: Hospital or nursing home confinement, surgery, trauma, malignant neoplasm, chemotherapy, neurologic disease with paresis, central venous catheter or pacemaker, varicose veins, and superficial vein thrombosis are independent and important risk factors for VTE.

Poststreptococcal reactive arthritis in adults: a case series.

OBJECTIVE: To guide primary care physicians regarding the diagnosis and treatment of poststreptococcal reactive arthritis (PSReA) in adults. PATIENTS AND METHODS: We retrospectively reviewed an indexed database of all patients evaluated or hospitalized between 1976 and 1998 at Mayo Clinic Rochester and identified 35 patients with the diagnosis of reactive streptococcal arthritis, arthralgia, or arthritides. Twenty-nine patients with the diagnosis of acute rheumatic fever (ARF), septic streptococcal arthritis, or nonspecific reactive arthritis were excluded. RESULTS: PSReA was confirmed in 6 adults (3 women, 3 men; age range, 25-66 years). All patients were symptomatic with polyarthritis and oligoarthritis disproportionate to the objective findings on physical examination. Although all patients had negative throat cultures at the onset of arthritis, increased titers of anti-DNase B and antistreptolysin O confirmed recent streptococcal infection. Antecedent events included pharyngitis in 3 patients (who had received a minimum of a 10-day course of penicillin) and toxic shock syndrome in 1 patient. The latency of onset of arthritis ranged from 4 days to 6 weeks. The arthritic symptoms had a protracted course beyond the typical maximum of 3 weeks described for ARF. Treatment with aspirin did not provide symptomatic relief in any of the patients, whereas the response to therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) was at least partial in all cases. Symptomatic relief occurred in 1 patient who received indomethacin and in 1 patient treated with prednisone. Penicillin prophylaxis was recommended in 1 patient. CONCLUSION: PSReA should be included in the differential diagnosis of all adult patients presenting with arthritis. Treatment strategies include aspirin, other NSAIDs, and corticosteroids. In adult patients with PSReA, there is no evidence to support the use of penicillin prophylaxis at this time.

Approaches to integrating data within enterprise healthcare information systems.

The benefits of an Enterprise Healthcare Information System are related in large part to the degree with which its data and the processes it supports are integrated. There are several technical approaches to achieve integration. The strategic decision to put a group or several groups of applications within a single product to improve integration depends on the degree to which best of breed solutions or an integrated whole is needed. It also depends on a number of factors specific to each organization. It is important to understand the challenge of interfaces before choosing the best solution.

Predictors of survival after deep vein thrombosis and pulmonary embolism: a population-based, cohort study.

BACKGROUND: Because reported survival after venous thromboembolism (VTE) varies widely, we performed a population-based retrospective cohort study to estimate survival, compare observed with expected survival, and determine predictors of short-term (< or =7 days) and long-term survival (>7 days) after VTE. METHODS: We followed the 25-year (1966-1990) inception cohort (n = 2218) of Olmsted County, Minnesota, patients with deep vein thrombosis alone (DVT) or pulmonary embolism with or without deep vein thrombosis (PE+/-DVT) forward in time until death or the last clinical contact. RESULTS: During 14 629 person-years of follow-up, 1333 patients died. Seven-day, 30-day, and 1-year VTE survival rates were 74.8% (DVT, 96.2%; PE+/-DVT, 59.1%), 72.0% (DVT, 94.5%; PE+/-DVT, 55.6%), and 63.6% (DVT, 85.4%; PE+/-DVT, 47.7%), respectively. Observed survival after DVT, PE+/-DVT, and overall was significantly worse than expected for Minnesota whites of similar age and sex (P<.001). More than one third of deaths occurred on the date of onset or after VTE that was unrecognized during life. Short-term survival improved during the 25-year study period, while long-term survival was unchanged. After adjusting for comorbid conditions, PE+/-DVT was an independent predictor of reduced survival for up to 3 months after onset compared with DVT alone. Other independent predictors of both short- and long-term survival included age, body mass index, patient location at onset, malignancy, congestive heart failure, neurologic disease, chronic lung disease, recent surgery, and hormone therapy. Additional independent predictors of long-term survival included tobacco smoking, other cardiac disease, and chronic renal disease. CONCLUSIONS: Survival after VTE, and especially after PE+/-DVT, is much worse than reported, and significantly less than expected survival. Compared with DVT alone, symptomatic PE+/-DVT is an independent predictor of reduced survival for up to 3 months after onset, implying that treatment for the 2 disorders should be different.

Trends in the incidence of deep vein thrombosis and pulmonary embolism: a 25-year population-based study.

BACKGROUND: The incidence of venous thromboembolism has not been well described, and there are no studies of long-term trends in the incidence of venous thromboembolism. OBJECTIVES: To estimate the incidence of deep vein thrombosis and pulmonary embolism and to describe trends in incidence. METHODS: We performed a retrospective review of the complete medical records from a population-based inception cohort of 2218 patients who resided within Olmsted County, Minnesota, and had an incident deep vein thrombosis or pulmonary embolism during the 25-year period from 1966 through 1990. RESULTS: The overall average age- and sex-adjusted annual incidence of venous thromboembolism was 117 per 100000 (deep vein thrombosis, 48 per 100000; pulmonary embolism, 69 per 100000), with higher age-adjusted rates among males than females (130 vs 110 per 100000, respectively). The incidence of venous thromboembolism rose markedly with increasing age for both sexes, with pulmonary embolism accounting for most of the increase. The incidence of pulmonary embolism was approximately 45% lower during the last 15 years of the study for both sexes and all age strata, while the incidence of deep vein thrombosis remained constant for males across all age strata, decreased for females younger than 55 years, and increased for women older than 60 years. CONCLUSIONS: Venous thromboembolism is a major national health problem, especially among the elderly. While the incidence of pulmonary embolism has decreased over time, the incidence of deep vein thrombosis remains unchanged for men and is increasing for older women. These findings emphasize the need for more accurate identification of patients at risk for venous thromboembolism, as well as a safe and effective prophylaxis.

Standardized problem list generation, utilizing the Mayo canonical vocabulary embedded within the Unified Medical Language System.

UNLABELLED: VOCABULARY: The Mayo problem list vocabulary is a clinically derived lexicon created from the entries made to the Mayo Clinic's Master Sheet Index and the problem list entries made to the Impression/ Report/Plan section of the Clinical Notes System over the last three years. The vocabulary was reduced by eliminating repetition including lexical variants, spelling errors, and qualifiers (Administrative or Operational terms). Qualifiers are re-coordinated with other terms, at run-time, which greatly increased the number of input strings which our system is capable of recognizing. IMPLEMENTATION: The Problem Manager is implemented using standard windows tools in a Windows NT environment. The interface is designed using Object Pascal. HTTP calls are passed over the World Wide Web to a UNIX based vocabulary server. The server returns a document, which is read into Object Pascal structures, parsed, filtered and displayed. STUDY: This paper reports the results of a recent Usability Trial focused on assessing the viability of this mechanism for standardized problem entry. Eight clinicians engaged in eleven scenarios and responded as to their satisfaction with the systems performance. These responses were observed, videotaped and tabulated. Clinicians in this study were able to find acceptable diagnoses in 91.1% of the scenarios. The response time was acceptable in 92.5% of the scenarios. The presentation of related terms was stated to be useful in at least one scenario by seven of the eight participants. All clinicians wanted to make use of shortcuts which would minimize the amount of typing necessary to encode the concept they were searching for (e.g. Abbreviations, Word Completion). CONCLUSIONS: Clinicians are willing to choose a canonical term from a suggested list (as opposed to their own wording). Clinicians want an "intelligent" system, which would suggest terms within a category (e.g. Types of "Migraine"). They are able to make functional use of our system, in its current state of development. Finally, all clinicians appreciate the value of encoding their problems in a standardized vocabulary, toward improved research, education and practice.

Clinical care management and workflow by episodes.

This paper describes the implementation of clinically defined episodes of care and the introduction of an episode-based summary list of patient problems across Mayo Clinic Rochester in 1996 and 1997. Although Mayo's traditional paper-based system has always relied on a type of 'episode of care' (called the "registration") for patient and history management, a new, more clinically relevant definition of episode of care was put into practice in November 1996. This was done to improve care management and operational processes and to provide a basic construct for the electronic medical record. Also since November 1996, a computer-generated summary list of patient problems, the "Master Sheet Summary Report," organized by episode, has been placed in all patient histories. In the third quarter of 1997, the ability to view the episode-based problem summary online was made available to the 3000+ EMR-capable workstations deployed across the Mayo Rochester campus. In addition, the clinically oriented problem summarization process produces an improved basic "package" of clinical information expected to lead to improved analytic decision support, outcomes analysis and epidemiological research.

Preoperative pulmonary evaluation. Identifying patients at increased risk for complications.

During surgical procedures, multiple physiologic changes affect the pulmonary system and its defense mechanisms. The presence of basic risk factors (eg, smoking, chronic obstructive pulmonary disease, severe obesity) can affect whether these physiologic changes result in pulmonary complications or even death. Therefore, the presence of risk factors should be ascertained in all patients before abdominal or thoracic surgery. The degree of risk can be further determined preoperatively by additional evaluation, such as pulmonary function testing, newer assessment of cardiorespiratory status, history taking, and physical examination. The presence of risk factors and the type of operation to be performed should guide decisions about whether to perform a procedure or to use prophylactic measures before and after surgery. New operative techniques may allow some procedures that were prohibited in the past to be performed in high-risk patients.

Implementing an EMR: paper's last hurrah.

The implementation of an electronic medical record system in any large organization is as complex a task as the design of the system. During implementation, it is necessary that health care providers using the electronic system are able to communicate with colleagues who are continuing to work with the paper record. The Mayo Clinic in Rochester, Minnesota, is well along the path to implementing an electronic medical record system. One of the key issues addressed has been the need for the electronic system to integrate with the paper record. This need to function in the dual electronic/paper environment has placed new demands on printers, required revision of some paper forms, and required the electronic system to create facsimilies of paper record forms. In addition, new security issues have been raised. Dual paper/electronic environment issues are an important challenge in the implementation of an electronic medical record.

Methemoglobinemia from topically applied anesthetic spray.

Topically applied anesthetic spray is commonly used as part of premedication for general anesthesia and for endoscopic procedures; it is rarely associated with side effects. In this report, we describe two cases of toxic methemoglobinemia that resulted from topically applied anesthetic spray used before endoscopy. In both cases, standard doses were used; however, methemoglobin levels of 45% and 38% developed within 1 hour of the procedure. Both patients had normal levels of erythrocyte methemoglobin reductase, an indication that this rare but potentially fatal side effect can occur in persons who have no predisposing factors. Because toxic methemoglobinemia is easily treated, our report emphasizes the need to recognize this problem when topically applied anesthetic sprays are used.

Prophylactic agents for venous thrombosis in elective hip surgery. Meta-analysis of studies using venographic assessment.

BACKGROUND: We determined the relative efficacy of various agents or combinations of agents in the prophylaxis of deep venous thrombosis after elective hip arthroplasty. METHODS: Peer-reviewed, English-language, human studies articles from 1975 through 1991 were obtained through a MEDLINE database search. Additional references were obtained from bibliographies. Articles that compared the effect of two or more prophylactic agents or placebo in preventing deep venous thrombosis as assessed by venography were selected for further review. Only studies of elective hip surgery in which all patients had venographic screening for thrombosis were included. Twenty-three of 101 studies met these criteria. Data were abstracted by one of us. Methodologic criteria and outcome data from each study were recorded and analyzed. RESULTS: There was significant heterogeneity in the deep venous thrombosis rate among studies. Although the rates were lowest for low-molecular-weight heparin with or without the use of stockings, adjusted-dose heparin, and warfarin, many agents had similar low rates. There was less heterogeneity when the relative risk was used as a summary statistic for studies in which two agents were compared. With pairwise comparisons, low-molecular-weight heparin performed better than every agent with which it was compared. Other agents performed well but were not consistently better. CONCLUSIONS: Multiple agents or combinations are effective prophylaxis for deep venous thrombosis, but none decreases the rate to zero. There was overlap in the 95% confidence intervals for the probability of deep venous thrombosis for various agents and especially for the probabilities for proximal thrombi. Many agents have not been compared directly with each other, but low-molecular-weight heparin consistently performed well.