Variabilities of serum total cholesterol and potassium results provided to 11 medical clinics were assessed using an audit sample-split specimen design. This involved collection of 3 tubes of blood from each of 302 patients, with 1 split specimen divided into 3 audit samples: 1 was sent to the original participating laboratory, another to a commercial referral laboratory, and the third to an academic referee laboratory. Two methods were used to assess variability of test results. Method 1 was based on result pairs corresponding to the split specimen and its corresponding audit sample. Method 2 was based on audit sample results only. The 2 methods provided comparable results for total cholesterol; the estimated coefficient of variation was 1.0% to 3.7%. However, method 1 consistently provided higher estimates of variability for potassium; the estimated SD was 0.096 to 0.168 mmol/L for method 1, while it was 0.035 to 0.090 mmol/L for method 2. Method 1 is more practical, but method 2 can provide a more accurate assessment of analytic variability. (+info)
Laboratory testing under managed care dominance in the USA.
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The uncontrolled escalation of total health care expenditure despite the government's endeavours during the past decades in the USA had led to the rapid infiltration of managed care organisations (MCOs). Traditional hospital based laboratories have been placed in a crucial situation with the advent of the managed care era. A massive reduction of in house testing urged them to develop strategies against financial difficulty. Consolidation and networking, participation in the outreach testing market, and emphasis on point of care/satellite laboratory testing in non-traditional, ambulatory settings are major strategies for the survival of hospital laboratories. Several physicians' office laboratories (POLS) have closed their doors in response both to regulatory restrictions imposed by the Clinical Laboratory Improvement Amendments of 1988 and to managed care infiltration. It seems likely that POLs and hospital laboratories will continue to reduce test volumes, whereas commercial reference laboratories will thrive through contracting with MCOs. In the current climate of managed care dominance in the USA, clinical laboratories are changing their basic operation focus and mission in response to the aggressively changing landscape. (+info)
An in-office diagnostic procedure to detect dermatophytes in a nationwide study of onychomycosis patients.
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PURPOSE: To evaluate in-office dermatophyte test medium (DTM) culture as an alternative to traditional laboratory fungal culture for confirming a diagnosis of onychomycosis, and to determine the prevalence of dermatophytes as a cause of onychomycosis in patients not participating in a clinical trial. DESIGN: This nationwide multicenter prospective study enrolled 1100 adult patients with suspect onychomycosis. DTM and laboratory fungal culture results were compared for individual patients. METHODOLOGY: The 310 participating physicians obtained patient nail-bed specimens and divided them for testing by both diagnostic methods. The paired results of the two culture methods were compared using the kappa statistic. PRINCIPAL FINDINGS: Paired culture results were available for 975 of the 1100 enrolled patients. DTM results agreed with central laboratory cultures in 70 percent of cases. The kappa value of 0.40 indicated a moderate degree of correspondence between the two testing modalities. Overall, DTM culture indicated a dermatophyte in 616 patient specimens (56 percent) and central laboratory culture identified a dermatophyte in 528 of the specimens (48 percent). For the entire study population, dermatophytes were identified in 93 percent of the positive central laboratory cultures, confirming that dermatophytes caused the vast majority of the infections. The cost of each DTM culture was approximately $1, compared to $25 for each laboratory fungal culture. CONCLUSION: This study demonstrates that the in-office DTM culture for diagnosing onychomycosis has comparable utility to the traditional laboratory fungal culture, is less expensive, and yields faster results. (+info)
A fundus camera dedicated to the screening of diabetic retinopathy in the primary-care physician's office.
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PURPOSE: To increase the number of diabetic patients being screened for retinopathy, an instrument, the DigiScope, was specifically designed to operate in primary-care physicians' offices. The DigiScope is described and its automated functions are evaluated. METHODS: The DigiScope consists of a semiautomated optical head to acquire fundus images, evaluate visual acuity, and transmit the data to a remote reading center through telephone lines. Normal volunteers and 17 consecutive diabetic patients visiting their primary-care physician were recruited, and nonophthalmic staff performed the acquisition session. RESULTS: The pupil center and working distance were set automatically. Centering was achieved within 750 microm in less than 500 ms. The fundus was successfully focused by an automated algorithm, and an imaging session covering 71 degrees of the posterior pole of both eyes lasted 5.6 +/- 2.4 minutes. It was found that a file-compression ratio of 12 did not degrade the clinical information and allowed data transfer in less than 6 minutes. A pilot study in normal eyes showed that the DigiScope images yielded the same amount of details as conventional color fundus photographs obtained by an expert photographer. CONCLUSIONS: The DigiScope fulfills the instrumental requirements for a practical and cost-effective tool to acquire data needed to identify diabetic patients who must be referred to an eye-care specialist. Widespread screening with the DigiScope may help reduce the risk of vision loss in an estimated 4 million individuals in the United States alone, who currently do not undergo an annual eye examination. (+info)
White coat effect in treated and untreated patients with high office blood pressure. Relationship with pulse wave velocity and left ventricular mass index.
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OBJECTIVE: To evaluate in hypertensive patients whether the white coat effect is associated with target-organ damage and whether it is modified by anti-hypertensive therapy. METHODS: In a cross-sectional study we evaluated blood pressure (BP) measured in the office and by 24-h ambulatory blood pressure monitoring (ABPM), carotid-femoral pulse wave velocity (PWV) as an index of aortic stiffness, and left ventricular mass index (LVMI) in 88 subjects (aged 49 +/- 2 years) with white-coat hypertension (WCH, office BP > 140/90, daytime BP < 130/84 mmHg), 31 under antihypertensive therapy, 57 untreated, and in 115 patients with office and ambulatory hypertension (HT, aged 51 +/- 2 years, office BP > 140/90, daytime BP > 135/85), 65 under antihypertensive therapy, 50 untreated. In a longitudinal study in 15 patients with HT and in 11 patients with WCH we evaluated the influence of antihypertensive therapy (> 6 months) on office and ambulatory BP and on PWV. RESULTS: The intensity of the white coat effect (office BP-daytime BP) was greater in WCH than in HT. Taking all subjects, the white coat effect did not correlate with PWV (r = 0.08, ns) or with LVMI (r = 0.01, ns), whereas daytime BP correlated significantly with PWV (r = 0.41, p < 0.01) and with LVMI (r = 0.32, p < 0.05). WCH subjects showed lower PWV and LVMI than HT subjects. Treated and untreated WCH, with similar office and daytime BP, showed similar values of PWV and LVMI. Treated and untreated HT showed similar office BP values but treated HT showed lower daytime BP and PWV values. In the longitudinal study, antihypertensive therapy significantly reduced daytime BP and PWV values in the 15 HTs, whereas in the 11 WCH it did not alter daytime BP or PWV values. CONCLUSIONS: 1. In both WCH and HT (treated and untreated) the intensity of the white coat effect does not reflect either the severity of hypertension measured by target organ damage or the efficacy of antihypertensive treatment. 2. In WCH antihypertensive therapy does not improve either ambulatory BP values or damage to target organs. (+info)
Magnitude and characteristics of arthritis and other rheumatic conditions on ambulatory medical care visits, United States, 1997.
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OBJECTIVE: To describe ambulatory medical care utilization, defined to exclude injury-related visits, for persons with arthritis and other rheumatic conditions. METHODS: National estimates, rates, and other characteristics of ambulatory care visits were calculated from a national sample of patient visits to physician offices and acute care hospital outpatient and emergency departments. RESULTS: An estimated 36.5 million ambulatory care visits were related to arthritis and other rheumatic conditions. Visit rates increased with age and, overall, were twice as high among women as men. Rates of visits by race varied by ambulatory care setting. Soft tissue disorders (9.3 million), osteoarthritis (7.1 million), nonspecific joint pain/effusion (7.0 million), and rheumatoid arthritis (3.9 million) were the most common diagnoses. CONCLUSIONS: Arthritis and other rheumatic conditions account for about as many ambulatory care visits as cardiovascular disease or essential hypertension. These visits serve as excellent opportunities to counsel patients regarding prevention messages for arthritis. (+info)
Azelnidipine and amlodipine: a comparison of their pharmacokinetics and effects on ambulatory blood pressure.
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We objected: 1) To compare the effects of azelnidipine and amlodipine on 24-h blood pressure; 2) To monitor the plasma concentration vs. the time profile in order to assess the association between pharmacokinetics and hypotensive activity after administration of either drug for 6 weeks. Blood pressure and pulse rate were measured by 24-h monitoring with a portable automatic monitor in a randomized double-blind study of 46 patients with essential hypertension. Azelnidipine 16 mg (23 patients) or amlodipine 5 mg (23 patients) was administered once daily for 6 weeks. Pharmacokinetics were analyzed after the last dose was taken. Both drugs showed similar effects on the office blood pressure and pulse rate. During 24-h monitoring, both drugs caused a decrease in systolic blood pressure of 13 mmHg and had a similar hypotensive profile during the daytime period (07:00-21:30). The pulse rate decreased by 2 beats/min in the azelnidipine group, whereas it significantly increased by 4 beats/min in the amlodipine group. Similar trends in the blood pressure and pulse rate were observed during the nighttime (22:00-6:30) and over 24 h. Excessive blood pressure reduction during the nighttime was not seen in either group. The pharmacokinetic results indicated that the plasma half-life (t1/2) of amlodipine was 38.5 +/- 19.8 h and that of azelnidipine was 8.68 +/- 1.33 h. Despite this difference in pharmacokinetics, the hypotensive effects of amlodipine and azelnidipine were similar throughout the 24-h administration period. (+info)
Health care utilization among older adults with arthritis.
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OBJECTIVE: To evaluate the effect of arthritis on subsequent 2-year use of health care services and out-of-pocket costs among older adults and determine if comorbidities or economic resources mitigate that effect. METHODS: Data were analyzed from 6230 participants interviewed in 1993 and 1995 in the Asset and Health Dynamic Survey Among the Oldest Old (AHEAD), a national probability sample of community-dwelling adults. Baseline arthritis status was ascertained from the report of an arthritis-related physician's visit or a joint replacement not associated with a hip fracture. The effect of baseline arthritis on the odds of subsequent 2-year health care utilization and high out-of-pocket expenses were estimated from multiple logistic regression controlling for demographic factors, comorbidity, and economic resources. RESULTS: Older adults with arthritis are significantly more likely to have a physician visit (odds ratio [OR] 3.0), hospital admission (OR 1.6), outpatient surgery (OR 1.3), receive home health care (OR 1.6), and have out-of-pocket cost >5000 US dollars (OR 1.6) compared with contemporaries having similar demographics (age, sex, racial/ethnic group, marital status), comorbid conditions, and economic resources (education, income, wealth, health insurance), but not reporting arthritis. CONCLUSIONS: Older adults with symptomatic arthritis reported greater medical utilization and cost compared with people not reporting arthritis. These disparities persisted after accounting for differences in demographics, comorbidities, and economic factors. These findings document greater economic burdens on a personal and societal level among people with arthritis. As individuals, older adults with arthritis spend more out-of-pocket dollars for health care than their contemporaries without arthritis. On a societal level, these findings of greater health care utilization among people with arthritis point to increasing future demands on the US health care system due to demographic increases in the numbers of older adults with arthritis and support policies aimed at improving arthritis prevention and treatment as well as reducing the economic disparities between those with and without arthritis. (+info)