Medical device tracking: results of a case study of the implantable cardioverter defibrillator.

Case reports were received of a fatal tachycardia caused by a malfunction of an implantable cardioverter defibrillator (ICD), a device that is subject to the tracking regulations of the Food and Drug Administration's Center for Devices and Radiological Health. The case reports led to a decision to notify 5,604 patients of the need for reprogramming of their ICDs to prevent the tachycordia. In the first 60 days, a total of 98.7% of the patients were successfully located and their devices reprogrammed. Multiple logistic regression analysis was conducted to examine an extensive array of factors that might have been related to the time to reprogramming. Patient-specific factors such as age, sex, and ejection fraction did not serve as a barrier to reprogramming in the first week (p = NS). Patients whose regular physician had >5 patients with the ICD subject to the recall were significantly more likely to have their ICDs reprogrammed in the first week (odds ratio [OR] 2.11, 95% confidence interval [CI] 1.85 to 2.43, p<0.001). Patients who changed physicians were significantly less likely to undergo reprogramming in the first week (OR 0.73, 95% CI 0.63 to 0.86, p<0.001). The experience of the recall of this tracked device is highly encouraging because it demonstrates that most tracked device recipients can be successfully located and receive medical intervention. Although tracking devices is a manufacturer's responsibility, the clinical community plays a critical role in its success. This report highlights the importance of understanding that role among physicians.

Mortality after aortic valve replacement: results from a nationally representative database.

BACKGROUND: Nationally representative estimates of in-hospital mortality after aortic valve replacement are needed to evaluate whether results from The Society of Thoracic Surgeons National Cardiac Surgery Database are applicable to other institutions in the United States performing these procedures. METHODS: Data from the 1994 Nationwide Inpatient Sample were used to estimate the patient characteristics and in-hospital mortality rates associated with aortic valve replacements performed in nonfederal hospitals in the United States. Procedural and hospital characteristics were examined for possible associations with in-hospital mortality. RESULTS: An estimated 46,397 aortic valve replacements were performed. In-hospital mortality occurred in 4.3% of first-time isolated aortic valve replacements and 6.4% overall. The highest quartile of procedure-specific hospital volume, compared with the lowest quartile, was associated with lower in-hospital mortality (adjusted odds ratio, 0.58; 95% confidence interval, 0.42 to 0.81). CONCLUSIONS: The in-hospital mortality rates observed in this study are very similar to those reported from The Society of Thoracic Surgeons database. These data provide substantial evidence that results from The Society of Thoracic Surgeons database are representative of those achieved at other institutions. However, procedure-specific hospital volume must be considered in applying these results to individual institutions.

The epidemiology of cardiac pacemakers in the older US population.

OBJECTIVES: This study estimates the age distribution of older patients (>64 years) receiving implantable cardiac pacemakers in non-federal US hospitals and determines major characteristics of this group using a massive, nationally representative sample of inpatient discharge records. DESIGN: Discharge records were obtained from the 1992 Nationwide Inpatient Sample. Correlation with census data from 1992 was used to determine age and gender specific rates. SETTING: The Nationwide Inpatient Sample is a 20% stratified probability sample of non-federal US hospitals. PATIENTS: Records of all recipients (26,425) of an initial or replacement pacemaker were selected. RESULTS: Individuals 65 years of age and older received an estimated 131,361 initial and replacement pacemaker pulse generators (87% of the total) in non-federal US hospitals in 1992. Pacemaker implantation was performed in urban teaching hospitals (28.9%), non-teaching urban hospitals (57.8%), and rural hospitals (13.3%). The age specific implantation rates per 100,000 population were 226.5 (age 65-74 years), 585.9 (age 75-84 years), 874.9 (age 85-94 years), and 540.4 (more than 94 years). The age-adjusted rate for men was 70% greater than the corresponding rate for women. Major diagnoses of implant recipients included atrioventricular block (37.8%) and atrial fibrillation (28.5%). Two percent of pacemaker recipients died before discharge. CONCLUSIONS: The rate of pacemaker implantation increases sharply up to age 95. As the number of older people in the US population grows, particularly those in the age ranges greater than 75 and 85 years, a sharply increased number of pacemakers will be implanted unless other factors decrease the need for these devices. The data also demonstrate diffusion of this technology from academic centers.

Reported complications of silicone gel breast implants: an epidemiologic review.

PURPOSE: To review the range of local and systemic complications attributed to silicone breast implants and to evaluate the epidemiologic literature on these complications. DATA SOURCES: Epidemiologic studies of the potential risks of silicone breast implants identified by MEDLINE search and literature review. STUDY SELECTION: Epidemiologic studies with cohort, case-control, and cross-sectional designs. When epidemiologic studies were unavailable (as for estimates of local complications), case series were reviewed. DATA EXTRACTION: Epidemiologic studies evaluated for methodologic quality, including such characteristics as study design, sample size and selection, determination of silicone exposure and outcome variables, and duration of follow-up. DATA SYNTHESIS: The epidemiologic literature on the potential complications of silicone breast implants has concentrated primarily on connective tissue disorders and cancer. Estimated of the true incidence of local complications, such as rupture, capsular contracture, and breast pain, are unavailable. Studies of scleroderma and other defined connective tissue diseases suggest that implant recipients have no substantially increased risk for these disorders; however, the epidemiologic literature is insufficient to rule out an association between breast implants and connective tissue disease-like syndromes. Overall, the rate of breast cancer does not seem to be increased in women with silicone breast implants. However, the risk to women as they reach the postmenopausal years in not yet known. CONCLUSIONS: Information is insufficient to adequately advise women who currently have or are seeking to obtain breast implants about the overall risk of these devices. No epidemiologic study has indicated that the rate of well-defined connective tissue disease or breast cancer has greatly increased in women with silicone breast implants, but no studies have ruled out a moderately increased risk for these diseases. No studies have adequately addressed the crucial issue of local complications such as rupture and capsular contracture, although evidence increasingly points to a higher risk for rupture as implants age.

Prevalence of latex-specific IgE antibodies in hospital personnel.

BACKGROUND: Rubber latex hypersensitivity is an important concern for health care workers. PURPOSE: The Center for Devices and Radiological Health, in collaboration with the Consumer Product Safety Commission, conducted a multicenter study of the prevalence of latex-specific IgE antibodies among United States hospital personnel. MATERIALS AND METHODS: Nine hospitals participated in the cross-sectional study. A total of 504 hospital personnel completed questionnaires that provided an array of demographic, occupational, and clinical information, including a history, if any, of allergies and the use of latex and nonlatex gloves. More than three-quarters (76.5%) of the participants were tested for total IgE and latex specific IgE. RESULTS: A total of 21 (5.5%, 95% CI = 3%-7%) of the tested participants were positive for the presence of latex specific IgE antibodies, defined as a latex IgE level of > or = 0.6 ng/mL. Latex specific IgE antibodies were more prevalent in participants who reported tachycardia, palpitations, flushing, or wheezing associated with latex gloves (Odds Ratio = 10.2, 95% CI = 3.7-28.6). CONCLUSION: The study's results suggest that the prevalence of latex-specific IgE antibodies among hospital personnel is appreciable and these personnel and their health care providers should be aware of this entity.

The epidemiology of pacemaker implantation in the United States.

Data on pacemaker implantation were obtained from the Medical Device Implant Supplement to the 1988 National Health Interview Survey, a nationally representative, population-based survey of 47,485 households (122,310 persons). The survey yielded an estimate of 456,482 noninstitutionalized adults with pacemakers (prevalence, 2.6 per 1,000). Prevalence rose significantly with age, from 0.4 per 1,000 among persons ages 18-64 to 26 per 1,000 among those ages 75 or older. Age-adjusted prevalence in males was 1.5 times that in females, and in whites 1.6 times that in nonwhites, although these differences were of borderline statistical significance. Prevalence did not vary significantly by region of residence, educational level, or income, but was significantly increased (more than threefold) in those reporting any activity limitation compared with those with no limitation. Fifteen percent of pacemakers in use were replacements; about one-fifth of these had been replaced more than twice. Sixty percent of previous pacemakers had been in place for at least 5 years. These data provide the first nationwide, population-based estimates of the epidemiology of pacemaker implantation, focusing particularly on the demographics of U.S. pacemaker recipients.

The epidemiology of prosthetic heart valves in the United States.

The Center for Devices and Radiological Health of the Food and Drug Administration, in collaboration with the National Center for Health Statistics, conducted the Medical Device Implant Supplement to the 1988 National Health Interview Survey, generating the 1st available population-based estimates of the use of prosthetic heart valves in the United States. The 1988 National Health Interview Survey was a massive, nationally representative cross-sectional survey that encompassed 47,485 households and 122,310 individuals. Data from the Medical Device Implant Supplement indicate that an estimated 253,283 persons with 279,175 heart valves were present in the civilian, non-institutionalized US population (population prevalence of 1.1/1,000, 95% CI 0.8-1.3). Prevalence of valve prostheses ranged from 0.2 per 1,000 in those age 44 and under to 5.3 per 1,000 in those 75 years of age and older. Age-adjusted prevalence of valve prostheses did not differ significantly according to sex, race, region of residence, education, or income of recipients. Two thirds of aortic valve recipients identified by the survey were male, compared with only one third of mitral valve recipients. Approximately two thirds of both aortic and mitral valve implants were reported as mechanical. Reported use of anticoagulative agents was significantly more common in recipients of mechanical than of bioprosthetic valves. The single most common reported reason for prosthetic valve implantation was rheumatic heart disease. These data provide useful epidemiologic and public health planning information on prosthetic heart valve use.

An overview of occupational hazards among veterinarians, with particular reference to pregnant women.

Veterinarians are challenged by an imposing group of occupational hazards, including exposure to ionizing radiation, injury, infectious agents, and chemicals. In this paper, the health hazards in the typical veterinary practice are inventoried, and the risks of each are assessed. During the past few decades, there has been a significant increase in women entering the veterinary profession. Information is presented concerning the impact of various occupational hazards on the health of female practitioners and paraprofessionals, particularly in regard to the reproductive system. Many of the occupational hazards are exclusively, or more significantly, detrimental to females (particularly when pregnant) and to their unborn. Women must be aware of and avoid these hazards in their clinical environment. The purpose of this review is to assist practitioners in identifying and assessing the hazards in their practice and determining what steps must be taken to eliminate or reduce them.

Prevalence of artificial hip implants and use of health services by recipients.

Data from the 1988 Medical Device Implant Supplement to the National Health Interview Survey are used to summarize information about the prevalence of artificial hips among adults in the United States. The 1988 National Health Interview Survey was a cross-sectional survey of the civilian noninstitutionalized United States population, and included 122,310 persons in 47,485 households in a multistage probability sample. The supplement supplied the first population-based estimates of prevalence and morbidity of selected medical devices. Projected to the United States population, the survey results indicate that an estimated 674,000 adults were using 811,000 hip implants. Hip implant recipients were significantly more likely to be older, to be white, and to have lower educational, income, and activity levels than the general population of adults. After age-stratification, however, only differences in activity limitation and race remained. Current economic outlays for hip replacement surgery are substantial. With the aging population, use of health services by patients with artificial hips will probably increase unless measures to reduce the need for replacement surgery are instituted. These measures include reducing injuries and improving biomaterials. Further investigation is needed to examine the activity limitation and racial difference in prevalence found in this study.

An estimation of squamous cell carcinoma risk from ultraviolet radiation emitted by fluorescent lamps.

The risk of squamous cell carcinoma (SCC) from ultraviolet radiation (UV) emitted by unfiltered fluorescent lamps was assessed. The assessment employed a mathematical power model based on human epidemiological data, which relates the SCC incidence in the United States white population to ambient solar UV. The annual numbers of new SCC on anatomical sites chronically exposed to solar UV (head/face/neck and hands) were estimated for indoor workers. Then the number of SCC that may be caused by additional UV exposure from indoor fluorescent lighting was estimated: the lifetime exposure of indoor workers to typical fluorescent lighting (if unfiltered) may add 3.9% (1.6-12%) to the risk from solar UV, resulting in the induction of an additional 1500 (600-4500) SCC per annum in the United States. This calculated projection must be compared with the 110,000 SCC caused by solar exposure. Thus, this analysis suggests there may be a small increased risk of SCC from exposure to UV-emitting fluorescent lamps.

Racial differences in the prevalence of intraocular lens implants in the United States.

We generated population-based estimates of the prevalence of intraocular lens implants by using the 1988 Medical Device Implant Supplement to the National Health Interview Survey. This national survey of a probability sample of the civilian noninstitutionalized United States population comprised 47,485 households and 122,310 persons. To produce national projections, we used survey respondent-reported data based on 1,941 reported intraocular lenses in 1,337 persons. Projected to the United States population, an estimated 2.6 million people had a total of 3.8 million lens implants. The predominant reason for the implant was cataract. The intraocular lens replacement rate was 0.9%. The use of intraocular lens implants was statistically significantly different from the general population in persons with the following socioeconomic characteristics: age (65 years or older), race (white), gender (female), annual family income (less than $20,000, although more commonly at or above the poverty threshold), and education (less than high school). The prevalence rates per 1,000 persons according to age were as follows: 0.3 for persons 44 years old or younger, 9.9 for persons 45 to 64 years old, 33.3 for persons aged 65 to 69 years, 63.5 for persons aged 70 to 74 years, and 113.5 for persons 75 years old or older.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of the veterinarian in hurricanes and other natural disasters.

Hurricanes create a multiplicity of complicated problems and hazards ranging from outbreaks of infectious disease to animal control problems precipitated by destruction of property. A multidisciplinary response is required to solve such problems. The pool of knowledge derived from various professionals interacting with multiple levels of government agencies (federal, state, and local) will provide the expertise needed. Because the veterinarian is trained to deal with disease involving populations of animals (e.g., herds or flocks) as well as individuals, and because of his/her intensive clinical training, the veterinarian is uniquely qualified to deal with the disaster situation. The veterinarian possesses extensive knowledge in disease and disease processes and has the capability of disease and injury management in affected populations, which qualifies him/her for an essential role, with unlimited potential as a member of any disaster relief team. There is considerable potential for veterinarians to play a role in responding to natural disasters. The areas of disease control, animal care, animal control, protection of the food supply, disinfection/sterilization, and planning are all areas where veterinarians can take an active part. Inclusion of the veterinarian in the process of planning for and responding to natural disasters will yield significant public health benefits.

Multi-state investigation of the actual disinfection/sterilization of endoscopes in health care facilities.

PURPOSE: The purpose of this investigation was to observe and assess the actual disinfection or sterilization of endoscopes in health care facilities. MATERIALS AND METHODS: A total of 22 hospitals and four ambulatory care centers in three states were studied. Facility protocols were reviewed, interviews conducted with relevant personnel, actual disinfection or sterilization procedures observed, and biologic tests performed to determine and assess disinfection/sterilization procedures. RESULTS: Fundamental errors observed during the course of the investigation included respective failures to time the period of disinfection, to clean all channels, to flush all channels with disinfectant, to fully immerse the endoscope in the disinfectant solution, and to use a disinfectant. At 78% of the facilities, failure to sterilize all biopsy forceps was observed. A total of 23.9% of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew 100,000 colonies or more of bacteria. These cultures were obtained after the completion of all disinfection/sterilization procedures and the device was deemed ready for use in the next patient. CONCLUSIONS: These data indicate that actual disinfection/sterilization procedures for endoscopes are not always optimal, and high-level disinfection of gastrointestinal endoscopes is not always achieved.

The relationship of maternal race and insurance status to prenatal ultrasound use in a national population.

Data from the first group of respondents (N = 4,846) of the 1988 National Maternal and Infant Health Survey were analyzed. After controlling for potentially confounding factors, such as maternal age, in a multivariate analysis, no relationship could be demonstrated between insurance status or race and the probability of receiving a prenatal ultrasound examination.

Seroprevalence of antibodies to the human immunodeficiency virus in dialysis workers: results of a multi-center study.

The Center for Devices and Radiological Health, in collaboration with the Department of Veterans Affairs Medical Center, Brooklyn, N.Y., conducted a multi-center, multi-institutional study of the seroprevalence of antibodies to the human immunodeficiency virus (HIV) among dialysis workers. Seven dialysis units and 112 dialysis workers participated in the study over a period of 2 years. Participation was limited to dialysis workers who, by questionnaire, denied non-occupational risk factors for HIV infection. The vast majority of the study participants were drawn from areas where the prevalence of HIV infection and AIDS cases are substantially greater than the national average. Study participants received the ELISA test for HIV antibodies. All 112 of the participants tested negative for HIV antibodies. These results are encouraging, as they failed to reveal unrecognized occupational transmission of HIV infection among dialysis workers.

Prevalence of artificial hips in the United States.

This report summarizes information about adults with artificial hips as derived from a national survey, the 1988 National Health Interview Survey Medical Device Implant Supplement. Based on extrapolation to the United States population from the survey sample, it is estimated that 674,000 adults are currently using 811,000 artificial hips. The prevalence rate is 3.8 persons per thousand (95% confidence interval, 3.2, 4.4). 91.5% of the implants are primary implants and 8.5% are revisions, with the predominant reason for revision being loosening. Arthritis and injury are the most common reasons for hip implantation. Almost 60% of the implants have been in use for 5 years or less. This prevalence information about adults with artificial hips is unique in that it represents the first such estimates based on a probability sample of the United States population.

Glove use by health care workers: results of a tristate investigation.

The Center for Devices and Radiological Health, in collaboration with the state health departments of Iowa, Maryland, and Massachusetts, conducted a multi-state, multi-institutional investigation of glove use by health care workers (HCWs). Twenty-two hospitals and four ambulatory care centers were included in the investigation. All 26 health care facilities were found to have adopted universal precautions policies for glove use by HCWs, per Centers for Disease Control guidelines. Four hundred five observations were made of HCWs performing procedures that may involve contact with patient body fluids, particularly blood. The prevalence of glove use during selected procedures was as follows: arterial blood gas procedures, 92.3%; intravenous line initiation/maintenance, 77.6%; and phlebotomy, 70.6%. Glove use during phlebotomy (p less than 0.001) and intravenous line procedures (p less than 0.05) was significantly lower in the state with a prevalence of the acquired immunodeficiency syndrome (AIDS) below the national average than in the states with a higher AIDS prevalence. The investigation suggests that health care facilities have responded to the Centers for Disease Control and Occupational Safety and Health Administration campaign to adopt universal precaution policies for glove use by HCWs. Actual glove use by HCWs appears to be substantial but not universal. Glove use by HCWs is significantly related to statewide AIDS prevalence.

How frequently are home pregnancy tests used? Results from the 1988 National Maternal and Infant Health Survey.

Many women use commercially available home pregnancy tests to determine their pregnancy status before seeking professional health care. Despite the increasing popularity of these products, no national estimates have been reported to date on their frequency of use. We analyzed available data from the 1988 National Maternal and Infant Health Survey to determine the frequency of use of home pregnancy tests during recent pregnancies of women of varying sociodemographic backgrounds. Approximately 33 percent (N = 4700) of the women surveyed used such a device. Use was most frequent among women who were white, married, over age 39 years, highly educated, or had a high family income. We conclude that home pregnancy testing appears to be a frequent procedure, especially among women of high socioeconomic background.

The effects of reprocessing cuprophane and polysulfone dialyzers on beta 2-microglobulin removal from hemodialysis patients.

To further define the relationship between dialyzer reuse and the removal of beta 2-microglobulin (beta 2M) during dialysis, 26 patients who received hemodialysis were studied. Thirteen patients were dialyzed with conventional cuprophane dialyzers, and thirteen patients were dialyzed with high-flux polysulfone dialyzers. Patients in each group were dialyzed with only new dialyzers during the primary-use phase of the study, and reprocessed dialyzers during the reuse phase. Dialyzers were used six times during the reuse phase. Serum beta 2M levels were measured both predialysis and postdialysis, and adjusted for fluid loss. Dialysis with conventional cuprophane new dialyzers during the primary-use phase of the study resulted in a 3.3% increase in serum beta 2M levels, and a 2.4% increase in serum beta 2M levels during the reuse phase. The difference in the change of the concentration of beta 2M between primary-use and reuse phases was not statistically significant. Dialysis with high-flux polysulfone new dialyzers during the primary-use phase was associated with a decrease of 59.5% in the mean postdialysis concentration of serum beta 2M compared with the predialysis level. A corresponding decrease of 62.6% in serum beta 2M levels was observed after dialysis with high-flux polysulfone reprocessed dialyzers during the reuse phase. These data show no evidence of an adverse effect on the clearance of beta 2M during dialysis from the reuse of dialyzers up to six times. The results confirm previous studies that have reported that high-flux dialysis with polysulfone dialyzers removes substantial amounts of beta 2M, and dialysis with conventional cuprophane dialyzers does not.