Intervals Before Tuberculosis Diagnosis and Isolation at a Regional Hospital in Taiwan

Article (PDF Available)inJournal of the Formosan Medical Association 106(12):1007-12 · December 2007with21 Reads
DOI: 10.1016/S0929-6646(08)60076-5 · Source: PubMed
Abstract
Nosocomial tuberculosis (TB) infection is still a problem in many Taiwanese hospitals. The objectives of this study were to explore the intervals before TB diagnosis and isolation at a regional hospital in Taiwan, and to provide useful knowledge to hospitals for the purpose of TB infection control. From 2002 to 2005, we included a total of 343 patients with culture-positive pulmonary TB in a regional hospital in Southern Taiwan for this study. Their medical records were reviewed, and the time intervals between patient-hospital contact points and isolation were recorded. Of 343 culture-positive pulmonary TB patients, the majority were male, over 40 years old, and unemployed. The mean interval between the first admission and isolation was 20.5 days (median, 2.0 days). The mean intervals between the first admission from outpatient clinics, emergency department and hospitalization and suspected TB were < 1 day, 6.07 days and 25.53 days, respectively. The mean accumulated exposure time was 0.35 days, 0.61 days and 10.09 days in outpatient clinics, the emergency department and hospitalization, respectively; 75.5% of patients had their diagnosis confirmed at the chest department of the department of internal medicine. Delayed diagnosis was most likely in the case of hospitalized patients and least likely in outpatient clinics. Delayed diagnosis in hospitalized patients also contributed more severely to TB exposure time than others. Enhancing the quality, speed and ability of specialists and physicians to diagnose TB, especially in emergency departments and in hospitalized patients, is essential.
J Formos Med Assoc | 2007 • Vol 106 • No 12
1007
After the SARS (severe acute respiratory syndrome)
outbreaks in 2003, nosocomial infection has be-
come an important issue in Taiwan’s hospitals.
Some outbreaks of nosocomial tuberculosis (TB)
infection were noted in several large hospitals
and proved by biomolecular techniques.
1
There-
fore, the issue of nosocomial TB attracted the
attention of the public. Especially, there were
closed and central air-conditioning systems in
most hospitals, most of which were experiencing
increasing numbers of patients. TB remains a wide-
spread infectious disease and is the most com-
mon notifiable communicable disease
2
in Taiwan.
The notification rate of confirmed TB was 70–80
Intervals Before Tuberculosis Diagnosis and
Isolation at a Regional Hospital in Taiwan
Yi-Chun Wu,
1,2
Gwo-Jong Hsu,
3
* Kenneth Yin-Ching Chuang,
4
Ruey-Shiung Lin
2
Background/Purpose: Nosocomial tuberculosis (TB) infection is still a problem in many Taiwanese
hospitals. The objectives of this study were to explore the intervals before TB diagnosis and isolation
at a regional hospital in Taiwan, and to provide useful knowledge to hospitals for the purpose of TB
infection control.
Methods: From 2002 to 2005, we included a total of 343 patients with culture-positive pulmonary
TB in a regional hospital in Southern Taiwan for this study. Their medical records were reviewed, and
the time intervals between patient-hospital contact points and isolation were recorded.
Results: Of 343 culture-positive pulmonary TB patients, the majority were male, over 40 years old,
and unemployed. The mean interval between the first admission and isolation was 20.5 days (median,
2.0 days). The mean intervals between the first admission from outpatient clinics, emergency department
and hospitalization and suspected TB were < 1 day, 6.07 days and 25.53 days, respectively. The mean
accumulated exposure time was 0.35 days, 0.61 days and 10.09 days in outpatient clinics, the emergency
department and hospitalization, respectively; 75.5% of patients had their diagnosis confirmed at the
chest department of the department of internal medicine.
Conclusion: Delayed diagnosis was most likely in the case of hospitalized patients and least likely in
outpatient clinics. Delayed diagnosis in hospitalized patients also contributed more severely to TB
exposure time than others. Enhancing the quality, speed and ability of specialists and physicians to
diagnose TB, especially in emergency departments and in hospitalized patients, is essential. [J Formos
Med Assoc 2007;106(12):1007–1012]
Key Words: infection control, interval, nosocomial infection, pulmonary tuberculosis, Taiwan
©2007 Elsevier & Formosan Medical Association
.......................................................
1
Fourth Branch Office, Centers for Disease Control, Department of Health,
2
Institute of Preventive Medicine, College of Public Health,
National Taiwan University, Taipei,
3
Department of Internal Medicine, Chia-Yi Christian Hospital, Chia-Yi, and
4
Infectious Disease
Laboratory, Department of Medicine Research, Chi-Mei Medical Center, Tainan, Taiwan.
Received: May 9, 2007
Revised: May 28, 2007
Accepted: September 4, 2007
*Correspondence to: Dr Gwo-Jong Hsu, Department of Internal Medicine, Chia-Yi Christian Hospital,
539 Chung-Hsiao Road, Chia-Yi 600, Taiwan.
E-mail: B347@cych.org.tw
ORIGINAL ARTICLE
cases per 100,000 population. The high preva-
lence in the community caused an increase in the
risk of nosocomial TB transmission in healthcare
facilities.
The incubation period of pulmonary TB, a con-
tagious disease transmitted by aerosols contain-
ing Mycobacterium tuberculosis,
3
is highly variable
and ranges from weeks to decades. Since rapid
microbiologic diagnosis of pulmonary TB remains
implausible, it is not uncommon for the diag-
nosis of TB to be heavily reliant on the clinical
experience of healthcare givers. Therefore, there
were a number of misdiagnoses or delayed diag-
noses in cases of pulmonary TB and transmission
potential, especially when patients were treated
by inexperienced physicians. In such a clinical
setting, these undiagnosed cases expose anyone at
those hospitals to M. tuberculosis-containing aero-
sols, with a subsequently greatly increased risk of
infection. The risk of nosocomial TB was substan-
tial, especially if immunocompromised patients
inhaled these contagious aerosols.
4
The most important infection control practice
for clinical management of cases with pulmonary
TB in health care settings is the prevention of
M. tuberculosis transmission, or the prevention
of nosocomial TB outbreak.
5–13
It has been rec-
ognized that if the time interval from hospital-
ization to isolation of infectious pulmonary TB
patients is more than 5.5 days, then healthcare
workers will have an increased risk of TB infec-
tion.
14
Likewise, Stroud et al found that in a case
of nosocomial TB, the median interval before iso-
lation was 6 days.
15
Theoretically, a decrease in
the time interval between admission and respira-
tory isolation among cases with smear-positive
pulmonary TB can decrease the probability of TB
transmission in hospitals. If the elapsed time can
be shortened to 2 days, it is possible to prevent
the transmission of M. tuberculosis.
15
Therefore, it is important to determine the
real situation of TB control in Taiwan’s hospitals.
The objectives of this study were to explore the
indices of nosocomial TB infection at a regional
hospital in Taiwan, and to provide useful strategies
for TB infection control for hospitals.
Methods
The study hospital, a regional hospital, is located
in Southern Taiwan. It has approximately 1000
beds, 2150 employees, and > 40 specialized de-
partments. There are > 3000 patients everyday in
the outpatient clinics, > 280 patients everyday
in the emergency department, and 25 negative-
pressure beds available for respiratory isolation.
From 2002 to 2005, patients who were newly
diagnosed with pulmonary TB infection with pos-
itive cultures in this hospital were included in
our study. Pulmonary TB with positive culture
was defined as a person who showed bacterio-
logic evidence of TB disease attained by sputum
culture.
Five infection control nurses were trained as
investigators. The medical charts of patients with
culture-positive pulmonary TB were reviewed by
these trained nurses. We collected the following
patient information: demographic data, occupa-
tion, medical history, specialty of the attending
physician, and the details of specific procedures
or events (including visits to outpatient clinics or
emergency department, hospitalization, and res-
piratory isolation, initial clinical suspicion of TB,
sputum microbiologic surveys, available micro-
biologic results, and prescription of anti-TB med-
ications). The timing of clinical suspicion of TB
was defined as the earliest day and time with the
coding of IDC-9-CM #011 as the diagnosis, or as
the earliest day and time of medical orders of
sputum acid-fast stains or anti-TB medication in
medical charts if there was a lack of TB diagnosis
records.
The intervals between patient-hospital con-
tacts and respiratory isolation were recorded. The
accumulated TB exposure time was defined as
the accumulated period in the hospital for pa-
tients with pulmonary TB infection before respi-
ratory isolation in negative-pressure single rooms.
Such clinical information about patients admitted
from the outpatient clinic or emergency depart-
ment, or those hospitalized for medical illnesses
other than for their respiratory symptoms, were
compared.
Y.C. Wu, et al
1008
J Formos Med Assoc | 2007 • Vol 106 • No 12
Statistical analysis
Statistical analysis was performed using STATA
version 8.0 (StataCorp LP, College Station, TX,
USA) and Microsoft Office Excel 2003. The χ
2
test was used to determine the association of cat-
egorical variables. A p value of less than 0.05 was
regarded to be statistically significant.
Results
A total of 343 patients with culture-positive pul-
monary TB were included. Their mean age was
62.8 years, with a range of 2–95 years. The major-
ity were aged 61–80 years (43.5%), and 1.8%
were younger than 20 years. The majority of pa-
tients were male, with a male-to-female ratio of
3.2. The majority (69.0%) of the 343 patients
were unemployed. About one third had a smok-
ing history, and 91 (26.5%) had diabetes mellitus
(Table 1).
Intervals between patient-hospital
contacts and respiratory isolation
The intervals between various clinical events are
shown in Table 2. In the table, the case numbers
are variable because we calculated only the effec-
tive study population. Among patient-hospital
contacts, the longest interval was between the
first day of admission and clinical suspicion of
pulmonary TB infection (mean, 9.5 days). The
mean total interval between the first day of ad-
mission and respiratory isolation was 20.5 days
(median, 2.0 days).
Intervals before TB diagnosis and isolation
J Formos Med Assoc | 2007 • Vol 106 • No 12
1009
Table 2. Mean interval between patient-hospital contact and respiratory isolation among patients with
pulmonary tuberculosis (TB)
Interval n Mean (d) Range
The first day of admission to clinical suspicion of TB 341 5.3 0.17 hr – 453.2 d
The day of clinical suspicion of TB to the order for 340 1.7 40.0 d – 365.0 d
acid-fast sputum stains
The day of order of acid-fast sputum stains to 337 3.6 0.17 hr – 194.0 d
sputum collection
The day of sputum collection to reporting results of 335 4.3 0.3 hr – 365.3 d
acid-fast sputum stains
The day of reporting results of acid-fast sputum stains to 148 8.5 0.1 hr – 732.3 d
initialization of anti-TB drugs
The first day of admission to respiratory isolation 133 20.5 0.5 hr – 453.2 d
Table 1. Clinical characteristics of 343 patients
with pulmonary tuberculosis
n (%)
Age (yr)
20 6 (1.8)
21–40 44 (12.8)
41–60 81 (23.6)
61–80 149 (43.5)
81 59 (17.2)
Missing data 4 (1.1)
Gender
Male 260 (75.8)
Female 82 (23.9)
Missing data 1 (10.3)
Occupation
Unemployed 235 (69.0)
Employed 76 (22.0)
Missing data 32 (9.0)
Smoking
Yes 119 (35.0)
No 224 (65.0)
Diabetes mellitus
Yes 91 (26.5)
No 252 (73.5)
Suspected intervals and accumulated TB
exposure time in outpatient clinics,
emergency department and hospitalization
As shown in Table 3, the mean interval between
first admission and suspicion of TB was the longest
(25.5 days) in the first admission from hospital-
ization and was shortest (0.07 days) in the first
admission from outpatient clinics. The average
accumulated TB exposure time was longest during
hospitalization (6.06 days per person) and short-
est at outpatient clinics (0.27 days per person).
Attending physicians who diagnosed
patients were primarily specialists in
pulmonary TB
The department of chest medicine (259, 75.5%)
was the major clinical division from which doc-
tors made the diagnosis of pulmonary TB, fol-
lowed by the department of infectious diseases
(13, 4%). About 20% of patients were diagnosed
by physicians of other specialties (Table 4).
Discussion
In this study, the age distribution of patients with
culture-positive pulmonary TB was similar to that
of national data reported by the Taiwan Centers
for Disease Control.
2
However, the male to female
ratio was slightly higher than the national data
(3.2 vs. 2.2).
2
The majority of patients in the pres-
ent study were unemployed. This ratio may also
be related to the elderly making up the majority
of these patients. One third of patients had a
smoking habit, and the correlation between pul-
monary TB and smoking needs further investiga-
tion. Diabetes mellitus was present in about one
fourth of patients, and it was also another issue
to be accounted for.
When the intervals between patient-hospital
contacts and respiratory isolation were evalu-
ated, the clinical pathways in diagnosis or treat-
ment of pulmonary TB were complicated, and
were sometimes outside of the Taiwan Centers
for Disease Control guidelines.
16
Every effort was
made to clarify any process between patient first
admission and isolation (including first day of
admission, clinical suspicion of TB, order for acid-
fast sputum stains, sputum collection, reporting
Y.C. Wu, et al
1010
J Formos Med Assoc | 2007 • Vol 106 • No 12
Table 4. Clinical departments that confirmed
tuberculosis diagnosis
Clinical department n (%)
Chest 259 (75.5)
Infection 13 (3.8)
Gastrointestinal 21 (6.1)
Metabolism 10 (2.9)
Others 40 (11.7)
Table 3. Interval and accumulated tuberculosis (TB) exposure time in outpatient clinics, emergency
department and hospitalization
Mean time interval or accumulated
n
time per person (d)
Interval between first day of admission and clinical
suspicion of TB infection
Patients from outpatient clinics < 1 152
Patients from emergency departments 6.07 155
Patients from hospitalization 25.53 34
Mean 5.33 341
Accumulated TB exposure time
Outpatient clinics 0.35 104
Emergency department 0.61 116
Hospitalization 10.09 80
results of acid-fast sputum stains, initiation of
anti-TB drugs, and respiratory isolation). However,
a few cases were beyond the clinical pathways,
and were managed by physicians’ judgment.
The mean interval between the first day of ad-
mission and respiratory isolation was 20.5 days
(Table 2). In other words, it took 3 weeks on aver-
age for culture-positive pulmonary TB to be iden-
tified in patients and isolated in negative-pressure
rooms from the time patients visited the hospital
for medical help. The median interval between
the first day of admission and respiratory iso-
lation was 2.0 days; there was a large difference
between the mean and median. The medians of
these intervals were much less than the mean
and closer to zero. The wide range of data may
have been the cause of the large difference. It also
revealed that the majority of these intervals were
less than 2 days. It is not clear whether the inter-
val was acceptable or not. Among patient-hospital
contacts, the longest interval was between admis-
sion and clinical suspicion of TB. It means that
during the clinical pathway of TB patient man-
agement, early detection or identification of TB
was a challenge. Other intervals described in this
study were first reported in Taiwan and they were,
to some degree, different from those of other
countries.
17–20
More investigations at other hos-
pitals are necessary to figure out the general picture
of the effectiveness and efficacy of TB infection
control programs, and thereafter these results
found in these investigations should become the
fundamental background for policy-making in
the prevention of nosocomial TB.
The most striking finding of our study was
that both suspected intervals and accumulated
TB exposure time in outpatient clinics, the emer-
gency department, and hospitalization led to the
same conclusion (Table 3): hospitalization takes
the longest time and outpatient clinics take the
shortest time. In other words, delayed diagnosis
of pulmonary TB occurred most often in hospi-
talized patients and led to the longest accumu-
lated TB exposure time. Patients in outpatient
clinics were least likely to experience delayed di-
agnosis and had the least accumulated exposure
time. The results also revealed that if there was
delayed diagnosis in hospitalized patients, it would
lead to a greater risk of nosocomial TB infection
than in other patients.
Elderly patients were hospitalized with a variety
of chronic diseases with complicated symptoms,
which often made it difficult for physicians to
determine what the major problems were. These
patients might have been hospitalized in other
departments for other symptoms. If the patients
were admitted to a non-internal medicine depart-
ment, the physicians often just focused on dis-
eases in their specialty and did not consider the
risk of TB infection. The clinical diagnosis of pul-
monary TB was often made by staff from the
department of chest medicine (Table 4). Most
likely, the physicians that patients encountered
during hospitalization or in the emergency depart-
ment were not chest physicians, but rather physi-
cians of other specialties or even non-specialized
resident physicians. The quality of TB diagnosis
was dubious. Therefore, enhancing the quality of
TB diagnosis in hospitalization and emergency
departments is necessary, and improving the ability
to diagnose TB in physicians of other specialties—
especially in emergency departments and during
hospitalization—is also important. Good quality
of diagnosis and clinical pathways, especially in
emergency departments and during hospitali-
zation, would decrease delayed diagnosis and
improve TB infection control in hospitals. Some
papers have also reported that the emergency de-
partment is a high risk area for TB transmission
and delayed diagnosis is abundant.
21,22
A high
index of suspicion, prompt isolation, and diag-
nosis of potentially infectious hospitalized patients
are needed to prevent TB transmission, especially
in elderly patients.
23–25
The data from our study are preliminary
results. Further investigation of other hospitals is
necessary in order to figure out the whole picture
and to provide useful indices for monitoring TB
infection control in hospitals.
To conclude, our findings indicate that the clini-
cal processes of TB diagnosis and treatment are very
complicated in hospitals, and delayed diagnosis is
Intervals before TB diagnosis and isolation
J Formos Med Assoc | 2007 • Vol 106 • No 12
1011
most likely to occur in hospitalized patients fol-
lowed by those in emergency departments. Delayed
diagnosis in hospitalized patients also contrib-
utes to more severe TB exposure time than others.
The quality of TB diagnosis in hospitalization
and emergency departments should be enhanced,
and improving the ability to diagnose TB in phy-
sicians of other specialties—especially in emer-
gency departments and during hospitalization—
is essential.
References
1. Centers for Disease Control and Prevention. Nosocomial
transmission of Mycobacterium tuberculosis found through
screening for severe acute respiratory syndrome—Taipei,
Taiwan, 2003. MMWR Morb Mortal Wkly Rep 2004;
53:321–2.
2. Centers for Disease Control, Department of Health.
Statistics of Communicable Diseases and Surveillance
Report Republic of China, 2005. Taipei: Centers for Disease
Control, Department of Health, The Executive Yuan, Taiwan,
R.O.C., 2006:144–8.
3. Tang JW, Li Y, Eames I, et al. Factors involved in the
aerosol transmission of infection and control of ventilation
in healthcare premises. J Hosp Infect 2006;64:100–14.
4. Dooley SW Jr, Castro KG, Hutton MD, et al. Guidelines for
preventing the transmission of tuberculosis in health-care
settings, with special focus on HIV-related issues. MMWR
Morb Mortal Wkly Rep 1990;39(RR-17):1–29.
5. Van Drunen N, Bonnicksen G, Pfeiffer AJ. A survey of
tuberculosis control programs in seventeen Minnesota
hospitals: implications for policy development. Am J Infect
Control 1996;24:235–42.
6. Carmine J, Bozzi Dale R, Burwen MD, et al. Guidelines for
preventing the transmission of Mycobacterium tuberculo-
sis in health-care facilities, 1994. MMWR Morb Mortal
Wkly Rep 1994;43(RR-13):1–132.
7. US Department of Health and Human Services. CDC:
Guidelines for Prevention of TB Transmission in Hospital.
Revised: October 1982.
8. A joint statement of IUATLD and the Tuberculosis Program
of the WHO: control of tuberculosis transmission in health
care settings. Tuberc Lung Dis 1994;75:94–5.
9. Jensen PA, Lauren A. Guidelines for preventing the trans-
mission of Mycobacterium tuberculosis in health-care
settings, 2005. MMWR Morb Mortal Wkly Rep 2005;
54(RR-17):1–141.
10. ACCP/ATS Consensus Conference: institutional control
measures for tuberculosis in the era of MDR/TB. Chest
1994;108:1690–710.
11. Davis YM, McGray E, Simone PM. Hospital infection control
practices for tuberculosis. Clin Chest Med 1997;18:19–33.
12. Cookson ST, Jarvis WR. Prevention of nosocomial trans-
mission of Mycobacterium tuberculosis. Infect Dis Clin
North Am 1997;11:385–409.
13. WHO. Guidelines for the Prevention of Tuberculosis in
Health Care Facilities in Resource-limited Settings. WHO/
TB/99.269, 1999.
14. Pearson ML, Jereb JA, Frieden TR, et al. Nosocomial
transmission of multidrug-resistant Mycobacterium tuber-
culosis. A risk to patients and health care workers. Ann
Intern Med 1992;117:191–6.
15. Stroud LA, Tokars JI, Gerico MH, et al. Evaluation of
infection control measures in preventing the nosocomial
transmission of multidrug-resistant Mycobacterium tuber-
culosis in a New York City hospital. Infect Control Hosp
Epidemiology 1995;16:141–7.
16. Centers for Disease Control, Department of Health.
Taiwan Guideline on TB Diagnosis and Treatment, 2
nd
edition. Taipei: Centers for Disease Control, Department
of Health, The Executive Yuan, Taiwan, R.O.C., 2006.
17. Moran GJ, McCabe F, Morgan MT, et al. Delayed recogni-
tion and infection control for tuberculosis patients in the
emergency department. Ann Emerg Med 1995;26:290–5.
18. Scott B, Schmid M, Nettleman MD. Early identification
and isolation of inpatients at high risk for tuberculosis.
Arch Intern Med 1994;154:326–30.
19. Rozovsky-Weinberger J, Parada JP, Phan L, et al. Delays in
suspicion and isolation among hospitalized persons with
pulmonary tuberculosis at public and private US hospitals
during 1996 to 1999. Chest 2005;127:205–12.
20. Bennett CL, Schwartz DN, Parada JP, et al. Delays in
tuberculosis isolation and suspicion among persons hospi-
talized with HIV-related pneumonia. Chest 2000;117:110–6.
21. Anathallee M, Curphey A, Beeching N, et al. Emergency
departments (EDs) in the United Kingdom (UK) are not
prepared for emerging biological threats and bioterrorism.
J Infect 2007;54:12–7.
22. Moran GJ, Fuchs MA, Jarvis WR, et al. Tuberculosis
infection-control practices in United States emergency
departments. Ann Emerg Med 1995;26:283–9.
23. Luby S, Carmichael S, Shaw G, et al. A nosocomial outbreak
of Mycobacterium tuberculosis. J Fam Pract 1994;39:21–5.
24. De Vries G, Sebek MM, Lambregts-van Weezenbeek CS.
Healthcare workers with tuberculosis infected during work.
Eur Respir J 2006;28:1216–21.
25. Counsell SR, Tan JS, Dittus RS. Unsuspected pulmonary
tuberculosis in a community teaching hospital. Arch Intern
Med 1989;149:1274–8.
Y.C. Wu, et al
1012
J Formos Med Assoc | 2007 • Vol 106 • No 12
    • "Recent reports of nosocomial TB outbreaks in Taipei, caused by delays in diagnosis and treatment [8,9], suggest that institutionalized TB reporting and DOTS alone may be insufficient to achieve targets established by Stop TB. In particular, previous studies have shown that TB diagnosis can be very complicated in hospitals, and delayed diagnosis is most likely to occur for hospitalized patients [10]. A recent study showed that TB patients in non-pulmonary/infectious disease wards had longer delays in suspicion, treatment, and respiratory isolation [11]. "
    [Show abstract] [Hide abstract] ABSTRACT: Current tuberculosis (TB) reporting protocols are insufficient to achieve the goals established by the Stop TB partnership. Some countries have recommended implementation of active case finding program. We assessed the effect of Cough Officer Screening (an active screening system) on the rate of TB detection and health care system delays over the course of four years. Patients who were hospitalized at the Changhua Christian Hospital (Changhua, Taiwan) were enrolled from September 2004 to July 2006 (Stage I) and August 2006 to August 2008 (Stage II). Stage II was implemented after a Plan-Do-Check-Act (PDCA) cycle analysis indicated that we should exclude ICU and paediatric patients. In Stage I, our COS system alerted physicians to 19,836 patients, and 7,998 were examined. 184 of these 7,998 patients (2.3%) had TB. Among these 184 patients, 142 (77.2%) were examined for TB before COS alarming and 42 were diagnosed after COS alarming. In Stage II, a total of 11,323 patients were alerted by the COS system. Among them, 6,221 patients were examined by physicians, and 125 of these patients (2.0%) had TB. Among these 125 patients, 113 (90.4%) were examined for TB before COS alarming and 12 were diagnosed after COS alarming. The median time from COS alarm to clinical action was significantly less (p = 0.041) for Stage I (1 day; range: 0-16 days) than for Stage II (2 days; range: 0-10 days). Our COS system improves detection of TB by reducing the delay from infection to diagnosis. Modifications of scope may be needed to improve cost-effectiveness.
    Full-text · Article · May 2010
  • [Show abstract] [Hide abstract] ABSTRACT: An approach to the systematic implementation of media-access-control (MAC)-level protocols is presented. The approach is based on the separation between the frame syntax analysis and the processing of data carried into its different fields. An example of protocol implementation in VHSIC hardware description language (VHDL) is given
    Conference Paper · Sep 1992 · Journal of the Formosan Medical Association
  • [Show abstract] [Hide abstract] ABSTRACT: In-hospital diagnosis delay (IHDD) of pulmonary tuberculosis (TB) has a significant impact on nosocomial TB transmission. We investigated the risk factors associated with prolonged IHDD in Taiwan, a high-resource, mid-incidence area. Between January 2005 and August 2006, we retrospectively enrolled 193 consecutive hospitalized patients. All of them had culture-proven pulmonary TB and did not receive antitubercular treatment at admission. IHDD was defined as the interval between admission and initiation of antitubercular treatment. Patients were grouped according to the median value of IHDD. The median IHDD was 7 days. Patients with IHDD > 7 days were considered the prolonged-delay group, and those with IHDD <or= 7 days, the short-delay group. Independent risk factors [with adjusted odd ratios (95% confidence intervals)] for prolonged IHDD were: negative sputum smear [47.53 (13.20-171.18), p < 0.001]; non-cavitary lesions on chest radiographs [14.90 (3.46-64.14), p < 0.001]; admission to hospital departments other than chest medicine/infectious diseases [6.60 (1.95-22.41), p = 0.002]; exposure to fluoroquinolones before antitubercular treatment [5.29 (1.13-24.75), p = 0.034]; underlying malignancy [4.59 (1.13-18.67), p = 0.033); and age > 65 years [3.19 (1.01-10.05), p = 0.048]. Death attributed to tuberculosis was associated with positive sputum smear (hazard ratio = 21.85; 95% CI = 2.74-174.44; p = 0.004) but not prolonged IHDD (p = 0.325). To minimize IHDD, clinicians should carefully manage hospitalized patients with risk factors for prolonged delay, such as those with negative sputum smears, non-cavitary lesions on chest radiographs, admission to departments other than chest medicine/infectious diseases, exposure to fluoroquinolones before antitubercular treatment, underlying malignancy, and age > 65 years.
    Article · Apr 2010
Show more