Estimates of the prevalence of arthritis and selected musculoskeletal disorders in the United States

OBJECTIVE

To provide a single source for the best available estimates of the national prevalence of arthritis in general and of selected musculoskeletal disorders (osteoarthritis, rheumatoid arthritis, juvenile rheumatoid arthritis, the spondylarthropathies, systemic lupus erythematosus, scleroderma, polymyalgia rheumatica/giant cell arteritis, gout, fibromyalgia, and low back pain).

METHODS

The National Arthritis Data Workgroup reviewed data from available surveys, such as the National Health and Nutrition Examination Survey series. For overall national estimates, we used surveys based on representative samples. Because data based on national population samples are unavailable for most specific musculoskeletal conditions, we derived data from various smaller survey samples from defined populations. Prevalence estimates from these surveys were linked to 1990 US Bureau of the Census population data to calculate national estimates. We also estimated the expected frequency of arthritis in the year 2020.

RESULTS

Current national estimates are provided, with important caveats regarding their interpretation, for self-reported arthritis and selected conditions. An estimated 15% (40 million) of Americans had some form of arthritis in 1995. By the year 2020, an estimated 18.2% (59.4 million) will be affected.

CONCLUSION

Given the limitations of the data on which they are based, this report provides the best available prevalence estimates for arthritis and other rheumatic conditions overall, and for selected musculoskeletal disorders, in the US population.

Osteoarthritis: new insights. Part 1: the disease and its risk factors

Osteoarthritis is the most common form of arthritis, affecting millions of people in the United States. It is a complex disease whose etiology bridges biomechanics and biochemistry. Evidence is growing for the role of systemic factors (such as genetics, dietary intake, estrogen use, and bone density) and of local biomechanical factors (such as muscle weakness, obesity, and joint laxity). These risk factors are particularly important in weight-bearing joints, and modifying them may present opportunities for prevention of osteoarthritis-related pain and disability. Major advances in management to reduce pain and disability are yielding a panoply of available treatments ranging from nutriceuticals to chondrocyte transplantation, new oral anti-inflammatory medications, and health education. This article is part 1 of a two-part summary of a National Institutes of Health conference. The conference brought together experts on osteoarthritis from diverse backgrounds and provided a multidisciplinary and comprehensive summary of recent advances in the prevention of osteoarthritis onset, progression, and disability. Part 1 focuses on a new understanding of what osteoarthritis is and on risk factors that predispose to disease occurrence. It concludes with a discussion of the impact of osteoarthritis on disability.

Occurrence of antibiotics in the aquatic environment

The recent monitoring of drug residues in the aquatic environment has gained much interest as many pharmaceutical compounds can frequently be found in sewage treatment plant (STP) effluents and river water at concentrations up to several microgram/l. This article describes the analysis of various water samples for 18 antibiotic substances, from the classes of macrolid antibiotics, sulfonamides, penicillins and tetracyclines. Samples were preconcentrated via lyophilization and quantified using HPLC-electrospray-tandem-mass spectrometry. The investigated STP effluents and surface water samples showed frequent appearance of an erythromycin degradation product, roxithromycin and sulfamethoxazole with concentrations up to 6 micrograms/l. Neither tetracyclines nor penicillins could be detected at concentration levels above 50 and 20 ng/l, respectively. From the large number of ground water samples that were taken from agricultural areas in Germany, no contamination by antibiotics was detected except for two sites. This indicates that intake from veterinary applications to the aquatic environment is of minor importance.

Treatment of multiple sclerosis with gamma interferon: exacerbations associated with activation of the immune system

We treated 18 clinically definite relapsing-remitting MS patients with recombinant gamma interferon in a pilot study designed to evaluate toxicity and dosage. Patients received low (1 microgram), intermediate (30 micrograms), or high (1,000 micrograms) doses of interferon by intravenous infusion twice a week for 4 weeks. Serum levels of gamma interferon were proportional to dose and no interferon was detected in CSF. Seven of the 18 patients had exacerbations during treatment, a significant increase compared with the prestudy exacerbation rate (p less than 0.01). Exacerbations occurred in all three dosage groups and were not precipitated by fever or other dose-dependent side effects. There were significant increases in circulating monocytes bearing class II (HLA-DR) surface antigen, in the proliferative responses of peripheral blood leukocytes, and in natural killer cell activity. These results show that systemic administration of gamma interferon has pronounced effects on cellular immunity in MS and on disease activity within the CNS, suggesting that the attacks induced during treatment were immunologically mediated. Gamma interferon is unsuitable for use as a therapeutic agent in MS. Agents that specifically inhibit gamma interferon production or counteract its effects on immune cells should be investigated as candidates for experimental therapy.

Exacerbations of multiple sclerosis in patients treated with gamma interferon

In an open, randomised study, 18 patients with clinically definite, relapsing-remitting multiple sclerosis (MS) received 1 microgram, 30 micrograms, or 1000 micrograms doses of recombinant gamma interferon (IFN-gamma), given by intravenous infusion twice a week for four weeks. 7 patients had exacerbations during treatment. This exacerbation rate, compared retrospectively with the pretreatment rate and prospectively with the post-treatment rate, was significantly greater than expected. Exacerbations were not precipitated by fever or other dose-dependent side-effects. A concomitant increase in circulating monocytes bearing class II (HLA-DR) surface antigen suggested that the attacks induced during treatment were immunologically mediated. IFN-gamma is unsuitable for treatment of MS.

Measles encephalomyelitis--clinical and immunologic studies

We studied 19 patients with postinfectious encephalomyelitis complicating natural measles-virus infections, and our results support the hypothesis that this demyelinating disease has a pathogenesis similar to that of experimental allergic encephalomyelitis. Early myelin destruction was demonstrated by the presence of myelin basic protein in cerebrospinal fluid, and lymphocyte proliferative responses to myelin basic protein were found in 8 of 17 patients tested. A lack of intrathecal synthesis of antibody against measles virus suggests that measles encephalomyelitis may not be dependent on virus replication within the central nervous system. Similar lymphoproliferative responses to myelin basic protein of lymphocytes from single patients with encephalomyelitis after rabies vaccine or after varicella or rubella virus infections suggest a common immune-mediated pathogenesis for the perivenular demyelinating disease that can follow the injection of neural tissues or infection by a variety of viruses.

Determination of antibiotics in different water compartments via liquid chromatography-electrospray tandem mass spectrometry

For the determination of 18 antibiotics in water samples down to the lower ng/l range, an analytical multi method is presented. The analytes belong to different groups of antibiotics such as penicillins, tetracyclines, sulfonamides and macrolid antibiotics. Samples were enriched using a universal freeze-drying procedure or a solid-phase extraction facultatively. Analysis was performed by liquid chromatography with electrospray-tandem MS detection. Chromatography required different columns and eluents. Mean recovery rates were in excess of 70%, however, with one exception and a quantitation limit of 50 ng/l for the tetracyclines and 20 ng/l for all other antibiotics were set.

Neuromonitoring and neurocognitive outcome in off-pump versus conventional coronary bypass operation

BACKGROUND

Cardiopulmonary bypass seems to be a major cause for both intraoperative microemboli and cerebral hypoperfusion. This study investigates high intensive transient signals (HITS) in transcranial Doppler ultrasound (TCD) and serum levels of the neurobiochemical marker protein S-100 in patients who underwent coronary artery bypass operation without cardiopulmonary bypass (off-pump CABG) in comparison with the conventional procedure using cardiopulmonary bypass (CPB). The results are related to the neuropsychologic outcome in both surgical groups.

METHODS

Forty patients were randomized in 2 groups (20 conventional and 20 off-pump CABG). Neurocognitive status was assessed preoperatively and postoperatively. Venous serum levels of S-100 protein were measured before and after coronary operation, HITS were measured in the middle cerebral artery during the operation.

RESULTS

The median value of HITS was 394.5 (0 to 2217) in the conventional versus 11 (0 to 50) in the off-pump group, p less than 0.0001. Postoperative S-100 serum levels were: 3.76 (0.13 to 11.2) microg/L (conventional) versus 0.13 (0.04 to 1.01) microg/L (off-pump), p less than 0.0001. Postoperative cognitive testing showed significantly different results with a postoperative impairment of 90% of the patients in the conventional group versus no impairment in the off-pump group.

CONCLUSIONS

Cognitive impairment seems to be strongly associated to CPB and the occurrence of micro-emboli. The off-pump technique appears to be promising in order to eliminate the source of these neuropyschologic impairments following CABG operation.

The prevalence of functional limitations and disability in older persons in the US: data from the National Health and Nutrition Examination Survey III

OBJECTIVE

To provide estimates by sex and age and by sex and race/ethnicity of the proportion of older Americans who have difficulty with functional limitations and daily activities.

SETTING

The Third National Health and Nutrition Examination Survey (NHANES III) 1988-1994.

DESIGN

A cross-sectional nationally representative survey.

PARTICIPANTS

All persons aged 60 and older who completed a household interview (N = 6,866) during NHANES III (conducted 1988-1994).

MEASUREMENTS

The self-reported physical and functional disability questions from NHANES III included: lower-extremity function, instrumental activities of daily living, basic activities of daily living, needing help with personal and routine daily activities, and use of assistive devices for walking.

RESULTS

Non-Hispanic black and Mexican-American men and women generally reported significantly (P < .01) more disability than did non-Hispanic white men and women. Disability was greater for minority women than for men. For both men and women, the prevalence in disability increased significantly (P < .01) with age for each measure.

CONCLUSIONS

These sex-age and sex-race/ethnicity national estimates of disability indicate that minority women may represent a vulnerable subpopulation.

Foot pain and disability in older women

In a study of the relation between foot pain and disability, a cross-sectional analysis was performed using baseline data (1992-1995) from the Women's Health and Aging Study, a population-based study of 1,002 disabled women aged 65 years and older living in Baltimore, Maryland. Chronic and severe foot pain, defined as pain lasting 1 month or longer in the previous year, plus pain in the previous month rated severe (7-10 on a scale of 0 to 10), was reported by 14% of the women. Severe foot pain was more common in women who were younger (aged 65-74 years), obese, or had hand or knee osteoarthritis. Walking speed and five repeated chair stands were slower in women with foot pain. After adjustment for age, body mass index, race, education, self-rated health, smoking status, comorbidities, and number of other pain sites, severe foot pain was independently associated with increased risk for walking difficulty (adjusted odds ratio = 1.69, 95% confidence interval 1.10-2.59) and disability in activities of daily living (adjusted odds ratio = 1.91, 95% confidence interval 1.21-3.01). These findings suggest that severe foot pain may play a key role in disability in older women. Further studies are warranted to confirm these results longitudinally and to determine whether interventions to alleviate foot pain could reduce or prevent disability in older women.

Successful chemotherapy of transfusion babesiosis

We describe babesiosis transmitted by transfusion. The infected blood donor was identified and a minimum period of infectivity of the donor's blood was established. We report a new modality for chemotherapy consisting of quinine plus clindamycin, and a new endemic focus for this zoonosis on Fire Island, New York. There are insufficient data to establish a reasonably safe period after which visitors and residents of Babesia-endemic foci can become blood donors. Screening of such persons by a rapid serologic test, such as the ELISA or immunofluorescent antibody tests, is suggested.

Thymopentin therapy reduces the clinical severity of atopic dermatitis

One hundred patients with moderate to severe atopic dermatitis were entered into a two-center, double-blind trial. Patients were randomized to receive either thymopentin (Timunox, n = 48) or placebo (n = 52), administered as daily subcutaneous injections for 6 weeks. Clinical extent of disease and severity parameters were measured at baseline and at regular time intervals during the study. Both the placebo- and thymopentin-treated groups demonstrated a progressive and statistically significant (p less than 0.001) decline in the overall severity of their disease, but reduction in the clinical severity score was higher in the thymopentin-treated group and statistically significant (p = 0.04) in comparison with the placebo-treated group after 6 weeks of treatment. Of the individual symptoms comprising the total severity score, pruritus (p = 0.02) and erythema (p = 0.04) were reduced significantly when thymopentin therapy was compared to placebo therapy. In addition, both the extent of body involvement and severity index (a combined severity/extent index) were significantly reduced after 6 weeks in the thymopentin-treated group in comparison to the placebo-treated group (p = 0.04). There were no serious adverse experiences in either treatment group. We conclude that treatment with thymopentin is safe and offers significant therapeutic promise for atopic dermatitis.

Kawasaki disease

This article is an up-to-date review of issues surrounding Kawasaki disease, with particular emphasis on the immunologic aspects. Kawasaki disease is now the leading cause of acquired heart disease in children in most developed countries.

Anti-CD3 F(ab')2 fragments are immunosuppressive in vivo without evoking either the strong humoral response or morbidity associated with whole mAb

The use of anti-CD3 monoclonal antibodies to treat organ allograft rejection has been complicated by (1) the morbidity associated with the initial dose, (2) the humoral response of the patients against the mAbs, and (3) the generalized immunosuppression induced by the mAbs. We investigated the potential of F(ab')2 fragments of the anti-murine-CD3 mAb, 145-2C11, to avoid these complications in the murine model. Both whole mAb and F(ab')2 fragments induced T cell depletion. However, injection of F(ab')2 fragments of anti-CD3 mAb did not cause T cell activation, and did not induce the morbidity and mortality observed following injection of whole mAb. The humoral response against the F(ab')2 fragments was significantly reduced compared with the response against the whole mAb. Furthermore, repeated administration of F(ab')2 fragments of anti-CD3 mAb resulted in prolongation of allogeneic skin graft survival superior to that seen following treatment with a single dose of whole mAb. Finally, while T cells from mice treated with whole mAb displayed profound suppression of in vitro CTL generation, T cells from mice treated with F(ab')2 fragments had significant in vitro CTL function. These results suggest that the use of F(ab')2 fragments of anti-CD3 mAb may offer significant advantages over whole mAb for the induction and maintenance of immunosuppression.

Cellular immune responses during complicated and uncomplicated measles virus infections of man

Lymphocytes from patients with measles showed profound and prolonged suppression of proliferative responses to mitogens. The degree of suppression was similar in patients with uncomplicated measles virus infection and in those with pneumonia or postinfectious encephalitis. Despite this suppression, lymphocyte responses to measles antigen and PPD were demonstrated in patients with encephalitis and uncomplicated disease, even early in infection. Most patients with pneumonia did not have demonstrable antigen-specific responses. The proportions of T helper (OKT 4) and T suppressor (OKT 8) cells and functional tests of Con A suppressor cell activity showed no significant difference between control and measles patients but, in contrast to controls, cells from measles patients cultured in the absence of any stimulant significantly suppressed the proliferation of allogeneic responder cells. Nine of 20 supernatant fluids from these cultures possessed a soluble suppressor factor. These studies indicate varied disruptions of immune reactivity during measles.

Association of the course of collagen-induced arthritis with distinct patterns of cytokine and chemokine messenger RNA expression

OBJECTIVE

To quantitate changes in cytokine and chemokine messenger RNA (mRNA) levels during the development and progression of collagen-induced arthritis (CIA) in mice.

METHODS

Mice with CIA were scored for arthritis and killed at weekly intervals. Cytokine and chemokine mRNA levels were determined by RNase protection assays of total paw RNA.

RESULTS

Arthritic paws exhibited mRNA levels of interleukin-1beta (IL-1beta), IL-2, macrophage inflammatory protein 2 (MIP-2), IL-6, IL-1 receptor antagonist, RANTES, tumor necrosis factor alpha (TNFalpha), TNFbeta, MIP-1alpha, IL-11, transforming growth factor beta1 (TGFbeta1), TGFbeta2, and TGFbeta3 that were increased above mRNA levels in paws of normal, unimmunized mice and that exhibited distinct temporal patterns of mRNA expression. Clinically uninvolved paws also exhibited an increase in mRNA levels of IL-11, RANTES, TNFalpha, TNFbeta, and MIP-1alpha.

CONCLUSION

The observed differential temporal cytokine and chemokine mRNA expression patterns suggest that specific cytokines and chemokines have defined roles at various times during the course of autoimmune arthritis. Since most of these cytokines and chemokines are found in human rheumatoid arthritis (RA) synovium and synovial fluids, these findings may have relevance to RA.

Familial aggregation of osteoarthritis: data from the Baltimore Longitudinal Study on Aging

OBJECTIVE

To evaluate the familial aggregation of osteoarthritis (OA) in a cohort of healthy volunteers drawn from a community setting.

METHODS

Hand radiographs obtained between 1978 and 1991 and bilateral standing knee radiographs obtained between 1984 and 1991 were read for changes of OA, using Kellgren-Lawrence (K-L) scales. The hand sites were distal interphalangeal (DIP) joints, proximal interphalangeal (PIP) joints, and first carpometacarpal (CMC1) joints. For each joint group, the presence of OA in at least 1 joint in a joint group, the number of affected digits in each joint group, and the sum of the K-L grade across all joints were analyzed. Polyarticular OA was recorded if there were OA findings in 2 of 3 hand joint groups plus 1 or both knees. Data from 167 families with hand radiographs, 157 families with knee radiographs, and 148 families with both hand and knee radiographs were analyzed for sib-sib correlations.

RESULTS

After adjustment for age, sex, and body mass index, clinically relevant sib-sib common correlations were found for OA of the DIP, PIP, and CMC1 joints, for OA at 2 or 3 hand sites, and for polyarticular OA (r = 0.33-0.81) when OA was defined according to the number of affected joints or as the sum of the K-L grade across all joints.

CONCLUSION

These results from a cohort of volunteers drawn from a community setting and ascertained without regard to OA status demonstrate familial aggregation of OA and contribute to the evidence for heritability of OA.

Low back pain and disability in older women: independent association with difficulty but not inability to perform daily activities

BACKGROUND

Low back pain is a highly prevalent chronic condition, yet little is known about the disabling effects of this common problem in older adults. This study examines the relationship between the presence and severity of low back pain and disability in older women.

METHODS

The study population was 1,002 disabled older women participating in a population-based prospective study of disablement. Key outcome measures of disability included level of difficulty and inability to perform the following daily activities: light housework, shopping, walking one-quarter mile, climbing stairs, lifting, and activities of daily living (ADLs).

RESULTS

Forty-two percent of participants reported they had low back pain for at least one month in the year before baseline. The prevalence of severe back pain decreased markedly with age (10% of those > or = 85 yr versus 23% in each of the two younger 10 yr age groups). After multivariate adjustments, women with severe back pain were 3 to 4 times more likely than other women to have a lot of difficulty with light housework or shopping. There was also an increased likelihood of difficulty with mobility tasks and basic ADLs among those with severe back pain. No associations were found between back pain and being unable to perform any of the daily activities studied, indicating possible differences in disablement processes leading to functional difficulties versus functional incapacity.

CONCLUSIONS

There was a strong association between back pain and functional difficulties in older women, pointing to the need for further research using longitudinal methods.

Entry overload, emergency department overcrowding, and ambulance bypass

OBJECTIVES

To describe an experience of emergency department (ED) overcrowding and ambulance bypass.

METHODS

A prospective observational study at Royal Perth Hospital, a major teaching hospital. Episodes of ambulance bypass and their characteristics were recorded.

RESULTS

From 1 July 1999 to 30 June 2001, there were 141 episodes of ambulance bypass (mean duration 187 min, range 35-995). Monday was the most common day with 39 (28%) episodes. Entry block alone was the most common reason bypass was activated (n=38, 30.4%). The mean number of patients in ED at these times was 40 (occupancy 174%), including nine in the corridor, seven awaiting admission, and 14 waiting to be seen. Episodes attributable to entry block were typically preceded by a presentation rate of >/=10 patients per hour for >/=2 hours (OR 6.2, 95% CI 4.3 to 8.5). Mid-afternoon to early evening was the most common time for activation. Ambulance bypass is increasing in frequency and duration.

CONCLUSIONS

Entry overload resulting in entry block results from overwhelming numbers of patients presenting to the ED in a short space of time. Entry block impairs access to emergency care. Unless something is done in the near future, the general public may no longer be able to rely on EDs for quality and timely emergency care. A "whole of system" approach is necessary to tackle the problem.

Cardiac troponin I in pediatrics: normal values and potential use in the assessment of cardiac injury

OBJECTIVE

To establish normal values and determine the impact of congenital or acquired heart disease on serum cardiac troponin I (cTnI).

METHODS

Concentrations of cTnI were measured in two groups of children. Group A represented ambulatory pediatric patients with no apparent cardiac disease (n = 120) and patients in stable condition with known congenital or acquired cardiac abnormalities (n = 96); group B was composed of patients admitted to intensive care units with normal echocardiograms (n = 16), with abnormal echocardiograms (n = 36), and those with blunt chest trauma who were thought to have cardiac contusions (n = 7).

RESULTS

The cTnI concentrations were generally less than 2.0 ng/ml in group A and frequently below the level of detection for the assay (1.5 ng/ml). There was no statistical difference between the two outpatient subgroups (p = 0.66). Nine intensive care patients had cTnI values greater than 2.0 ng/ml. Six of these patients, all with abnormal echocardiograms, had values less than 7.7 ng/ml. All improved and had subsequent normal cTnI concentrations. None of the three remaining patients (two with systemic illness (trauma and sepsis) and one with severe pulmonary hypertension), all with values greater than 8.0 ng/ml, survived. Three of the four patients with high likelihood of cardiac contusion had cTnI concentrations greater than 2.0 ng/ml (including one patient who died).

CONCLUSIONS

Cardiac troponin-I values are generally not elevated in children with stable cardiac disease or general pediatric conditions. In the context of severe acute illness, significant elevation of cTnI may be an indicator of poor outcome. Elevation of cTnI may also have diagnostic value in cases when cardiac contusion is suspected.

Prevention of autoimmune diabetes with nonactivating anti-CD3 monoclonal antibody

Autoreactive T cells mediate diabetes in animal models of insulin-dependent diabetes mellitus (IDDM) and are believed to cause the disease in humans. Therefore, immunotherapies directed against T cells are of particular interest for the treatment of IDDM. One candidate for such immunotherapy is anti-CD3 monoclonal antibodies (MoAbs), but clinical side effects are common with anti-CD3 treatment due to the ability of these MoAbs to activate T cells in vivo. However, F(ab')2 fragments of anti-CD3 are nonactivating and immunosuppressive. We evaluated the effects of whole anti-CD3 MoAb and F(ab')2 fragments in the setting of experimental autoimmune diabetes. Treatment with whole MoAb or F(ab')2 fragments significantly reduced the hyperglycemia induced with multiple low dosages of streptozocin (MDSDM; 232 +/- 23 mg/dl, P less than 0.01 and 235 +/- 16 mg/dl, P less than 0.01 vs. 325 +/- 25 mg/dl, respectively) in male CD1 mice. Both whole MoAb and F(ab')2 fragments suppressed the development of insulitis (P less than 0.001). Treatment with whole MoAb resulted in marked weight loss (10.4 +/- 1.5% of total body wt), and the mice appeared ill and listless, whereas, mice treated with F(ab')2 fragments gained weight (4.9 +/- 5.5% of total body wt) and appeared healthy. Treatment with whole MoAb caused activation of T cells in vivo as reflected by proliferation of freshly isolated spleen cells to recombinant interleukin-2. Depletion of T cells with whole MoAb was more pronounced than with F(ab')2 fragments, and T-cell receptor (TCR) reexpression on remaining cells occurred with F(ab')2 fragments within 48 h after F(ab')2 treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Maternal characteristics and toddler temperament in infantile anorexia

OBJECTIVE

To explore the association between specific maternal characteristics, maternal perceptions of toddler temperament, and infantile anorexia.

METHOD

Three groups of toddlers (aged 12-37 months) participated in this study: toddlers with infantile anorexia (n = 34), picky eaters (n = 34), and healthy eaters (n = 34). Mothers completed questionnaires that assessed their own eating attitudes, marital satisfaction, and their toddlers' temperament, and an interview that explored their attachment representations. Mothers and toddlers were videotaped during a feeding session, and toddlers were weighed and measured.

RESULTS

Temperament ratings differentiated between infantile anorexics and healthy eaters (p < .0001), with infantile anorexics receiving higher difficulty, irregularity, negativity, dependence, and unstoppable ratings. Mothers of anorexics showed greater attachment insecurity than mothers of healthy eaters (p < .05), but they demonstrated neither overt eating pathology nor less marital satisfaction than the other groups. Thirty-nine percent of variance in feeding conflict was explained by toddlers' diagnoses, temperament ratings, and maternal characteristics. Twenty-one percent of variance in toddlers' weights was explained by temperament ratings and feeding conflict.

CONCLUSION

Maternal characteristics and perceptions of their toddlers' temperament characteristics should be addressed in treatment for infantile anorexia.

An analysis of emergency department use by patients with minor illness

STUDY OBJECTIVE

To describe the motivation for emergency department use by patients with minor illnesses and compare the demographics and social class characteristics of these patients with those of the general ED population.

DESIGN

Observational, case-control study.

SETTING

Urban ED.

TYPE OF PARTICIPANTS

A sample group of 325 adult, nongeriatric patients with minor illnesses was selected by screening all patients registering in the ED between 9:00 AM and 6:00 PM on 15 randomly selected weekdays. A patient was included in this study group if the chief complaint, method of arrival, and subsequent evaluation met predetermined criteria for minor illness. A comparison group (control) was composed of all ED patients (224) who presented during two randomly selected 24-hour periods that did not overlap with the times of study group enrollment.

INTERVENTIONS

Sample group patients were interviewed concerning their socioeconomic backgrounds, reasons for using the ED, and perceptions of the urgency of their conditions. Comparison group patients' interviews were confined to the collection of demographic and socioeconomic information.

MEASUREMENTS AND MAIN RESULTS

There were more men (P = .12), more self-pay patients (P = .017), and fewer Medicare patients (P less than .001) in the study group. There also was a strong trend toward higher income (P = .059) in the study group. The racial, marital, employment, and educational backgrounds of the two groups were similar. Eighty-two percent of the study group had no chronic illness, and only 36% reported a problem of more than three days' duration. Patients chose to use the ED because of its convenience (23.7%), the absence of previous provider relationships (22.1%), and the inability to make a prompt appointment with their regular provider (19.0%). Major differences existed between the reasons for which different demographic and socioeconomic groups chose ED care. Study group patients believed that less than 24 hours should elapse between the onset of their problem and the time at which they receive medical care.

CONCLUSION

There are no major differences in ED use for minor illness patients from different racial, educational, and economic backgrounds. These patients tend to have a low frequency of chronic illness and often have no established health care provider. They choose the ED for its ease of access and the wide scope of care that can be delivered.

A prospective study of acute hypoxic respiratory failure

A prospective study of acute hypoxic respiratory failure was carried out by nine centers in a collaborative NIH study from 1 September 1975 to 1 March 1977. Serious hypoxic respiratory failure was defined in 713 patients by the presence of (1) endotracheal intubation and positive airway pressure for at least 24 hours, and (2) the administration of at least 50 percent oxygen. The 490 patients between 12 to 65 years of age had a mortality of 61 percent. Mortality increased with increasing organ failure: one organ system failure (lung only) 40 percent; two, 54 percent; three, 72 percent; four, 84 percent, five, 100 percent. Only 103 patients died with isolated lung failure, whereas 353 died of a combination of lung and other organ failures. Both the overall mortality (66 percent) and the mortality of those with only isolated lung failure (40 percent) were much higher than anticipated for the selection criteria.