CHS Research News
Vol 17, Issue 3, Fall 2005
Center News
by Joan DeClaire
New Findings
New Group Health study finds association
between common childhood infection and neurologic conditions
A new study adds support to an increasing body of evidence that the
common childhood bacterial infection known informally as strep throat is
associated with an increased risk for some neurologic conditions that
frequently start in childhood—Tourette’s syndrome (TS), obsessive-compulsive
disorder (OCD) and tic disorder.
The study, conducted at the Group Health Center for Health Studies (CHS)
in Seattle, is published in the July 5, 2005 edition of the journal
Pediatrics, accessible online at
www.pediatrics.org. It suggests that strep throat (streptococcal
infection) doubles the risk for a first diagnosis of TS, OCD or tic disorder
within three months after infection. Multiple infections appear to
approximately triple the risk for a first diagnosis of these disorders
within 12 months.
"There are likely a number of different causes for these conditions,
which often show up first in childhood or adolescence," explained Robert L.
Davis, MD, MPH, senior researcher at CHS and the study’s corresponding
author. "Following a number of different leads from past research, we’ve
found more tantalizing clues about possible connections between childhood
infections and certain disorders. However, our findings certainly don’t
suggest that there is any immediate need for a change in medical—or
parental—practice."
Davis did not suggest that parents and physicians should be more worried.
Nor did he suggest parents do anything differently if their child gets strep
throat. "Right now, this is all still in the research stage," said Davis.
"We still don’t know if treatment with common antibiotics helps prevent
these neurologic conditions that might follow strep throat, or reduce their
severity, or shorten their duration if they do occur."
These disorders are more common than previously appreciated. OCD affects
1–2 percent of school-age children, and transient tics can affect up to
10–25 percent of elementary school-age children. Some researchers suspect
the body’s natural response to infection—the production of certain
antibodies directed to parts of the brain—might be linked in some way to
pediatric autoimmune neuropsychiatric disorders (PANDAS), including TS, OCD,
and tic disorder.
"Although the presence of these antibodies is more frequent among
children with tics or TS, there’s much we still don’t know," said Davis.
"For example, why do millions of children get strep throat every year, but
only a tiny fraction develop these disorders?"
Davis and other researchers think that a person’s genes may play a
critical role. One theory is that the strep infection might serve as a
trigger for symptoms in only those children who carry a particular gene or
set of genes. "It’s a promising avenue for additional study," Davis said.
The study examined the medical records of 202 pediatric patients with TS,
OCD or tic disorder at Group Health, occurring between 1992 and 1999.
Children were more than twice as likely as a control group (who did not have
the disorders) to have had at least one streptococcal infection in the three
months before disease onset, and almost twice as likely to have had a least
one streptococcal infection in the 12 months before onset. Incidence of the
disorders was more than three times as common among patients who’d had two
or more step infections in the year before onset.
Other study authors include Loren K. Mell, MD, of the Pritsker School of
Medicine, University of Chicago, and David Owens, MD, of the University of
Washington School of Medicine.
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CHS and UW experts review top ten medical findings
What recently published medical research is most important for practicing
clinicians? That’s the question answered in an article by Group Health
Center for Health Studies Director Eric
B. Larson, MD, MPH, and University of Washington (UW) Professor of
Medicine John V.L. Sheffield, MD.
In the August 2, 2005 issue of the Annals of Internal Medicine,
Larson and Sheffield cite studies in 10 areas that commonly concern
patients, including weight loss, anti-inflammatory drugs, hormone therapy,
and prostate cancer prevention. In addition to the print report, the
information is shared online with more than 119,000 physicians who are
members of the American College of Physicians, the nation’s largest medical
specialty organization.
"With tens of thousands of scientific papers published each year, no one
physician could possibly keep up with all the new findings that are
important to his or her clinical practice," said Larson. Reviews like this
in Annals highlight the year’s most important findings as determined
by a systematic review by experts.
The studies cited in Larson and Sheffield’s article were selected by
authorities in internal medicine—a broad-ranging specialty that focuses on
prevention and treatment of adult diseases. The authors surveyed general
internal medicine physicians and sub-specialists from the University of
Washington Medical School, along with editors of the American College of
Physicians’ Journal Club.
"Our article is designed to tell internists and primary care physicians,
‘Pay close attention to these findings in particular because they will make
a difference in the way you treat your patients’ most common problems,’"
said Larson, who has teamed up with Sheffield to co-author the Annals
annual update five times in the past nine years.
"This is the first year that we found something definitive for physicians
to say about weight loss programs," said Larson, referring to studies that
demonstrated the health benefits of adherence to regulated diets.
Larson also pointed to important evidence emerging in the area of
prostate cancer, where a recent study showed that a rapid increase in PSA
levels in the year before diagnosis may indicate that a man is at a higher
risk for dying of prostate cancer despite undergoing surgery. "Prostate
cancer is an area where doctors and patients are continuously dealing with
uncertainty," said Larson. "But the evidence base is growing and that’s
helpful."
Findings related to the hazards of the COX-2 inhibitors such as Vioxx
show the growing importance of "post-marketing studies to monitor long-term
drug safety," the authors wrote. They also touted the past year’s "victories
for such common-sense approaches as exercise, self-monitoring, and smoking
cessation."
Top 10 findings cited in Annals’ 2005 "Update
in General Internal Medicine"
1) Cardiovascular disease and statin use: Two studies—one in
patients with type 2 diabetes, and one in patients with coronary artery
disease—both showed that statin drugs were more effective than previously
thought in preventing cardiovascular problems.
2) Management of coronary artery disease: Percutaneous coronary
intervention (PCI) procedures such as angioplasty and the insertion of
stents to open narrowed coronary arteries may not be that valuable in
certain people. In fact, one study showed that aerobic exercise was more
effective than PCI for certain patients. Another study found that having
PCI prior to heart surgery did not did not substantially alter the
long-term outcome for some patients.
3) Hypertension: In elderly patients with hypertension, home
measurement of blood pressure predicted cardiovascular problems more
accurately than blood pressure measured in medical centers. This suggests
the value of self-monitoring over time in the management of high blood
pressure.
4) Weight loss programs: Studies comparing various diets found
that adherence to any regulated diet—not a particular diet
itself—was the most important predictor of the weight loss achieved and of
improvements in other health outcomes.
5) Cyclooxygenase-2 (COX-2) inhibitors: Earlier studies showing
a link between selective COX-2 inhibitors such as Vioxx and increased risk
of heart attacks and strokes caused some of these drugs to be withdrawn
from the market in 2004. Physicians should prescribe COX-2 inhibitors with
caution, especially for patients with moderate to high cardiovascular
risk.
6) Hormone replacement therapy (HRT): Previous studies showed
that HRT increases the risk for heart disease and invasive breast cancer
in postmenopausal women with a uterus. One new study shows the same risks
in postmenopausal women with previous hysterectomy. Another shows that HRT
does not prevent dementia. These studies provide further evidence that
postmenopausal women should not take HRT for the general prevention of
chronic disease.
7) Dementia: The anticholinesterase inhibitor donepezil, a
commonly prescribed generic drug for Alzheimer’s disease, may produce
modest improvements in symptoms, but probably does not alter the course of
the disease. Physicians should individualize the decision to prescribe
this drug and should pay careful attention to clinical response and
adverse effects.
8) Pulmonary medicine: Patients with chronic obstructive
pulmonary disease (COPD) had improved health outcomes when they used a
newer once-daily bronchodilator called tiotropium rather than an older
drug called ipratropium. Although tiotropium is more expensive, the
increased cost is justified because it reduced exacerbation and improved
lung function and quality of life.
9) Prostate cancer: A single prostate-specific antigen (PSA)
blood test does not accurately measure a man’s risk of dying of prostate
cancer because the tests often give false negative or false positive
results. Recent studies indicate that measuring velocity—i.e., how quickly
PSA levels rise over time—is probably a better way to predict which men
might benefit from prostate cancer treatment in addition to surgery. Men
whose PSA levels increase more than 2.0 ng/mL in the year before diagnosis
may have a higher risk for dying of prostate cancer despite undergoing
radical prostatectomy.
10) Preventive medicine: The authors noted three findings in
this area: 1) A new vaccine against Human Papilloma Virus (HPV) prevented
cervical infection and abnormalities that indicate a precancerous
condition. "The vaccine may be licensed soon and offers real promise for
reducing cervical cancer incidence," the authors wrote. 2) Vitamin D
supplementation in older people with stable health was associated with a
20 percent reduction in the risk for falls, possibly because of improved
muscle function. 3) Early and intensive cigarette use was linked to
highest mortality among smokers. The earlier the age of smoking cessation,
the more years of life expectancy gained.
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Psaty named CHS Senior Investigator
Group Health Center for Health Studies faculty voted in July to name
University of Washington Professor of Medicine and Epidemiology Bruce Psaty,
MD, PhD, a senior investigator on the CHS faculty. Psaty will continue
to serve as co-director of the UW’s Cardiovascular Health Research Unit.
He has held the status of "affiliate investigator" with CHS for several
years as the two organizations have collaborated on a variety of important
pharmacoepidemiologic studies involving Group Health members.
"This new appointment as a CHS senior investigator acknowledges the
tremendous contribution Bruce and his research team make to our scientific
enterprise and how deeply integrated our work has become," said CHS Director
Eric B. Larson, MD, MPH.
Psaty is widely recognized for efforts to alert health professionals,
government leaders, and the public to the risks and benefits of various drug
therapies, including lipid-lowering drugs, high blood pressure medications,
and COX-2 inhibitors. He is a national leader in encouraging better
post-market surveillance of Food and Drug Administration-approved
medications. UW honored Psaty with its Outstanding Public Service Award
on June 9 for these efforts.
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Research Highlights
A media campaign and $1 per pack cigarette tax increase would reduce
overall smoking rates, decrease deaths attributable to smoking, and reduce
net societal costs according to a study led by CHS Associate
Investigator Paul Fishman, PhD,
and published in the July 2005 issue of the American Journal of
Preventive Medicine. The study featured an analysis conducted from a
societal perspective to estimate the cost-effectiveness of an anti-smoking
media campaign and cigarette tax increase on the lifetime decrease in
smoking-attributable deaths among the cohort of all 18-year-olds in the U.S.
during the year 2000. This design reflected the fact that most people begin
smoking before age 21, meaning that the largest impact on smoking-related
mortality is likely to come from campaigns aimed at young people.
Acupuncture did not perform better than sham acupuncture at relieving
pain caused by the common chronic pain condition fibromyalgia according
to a study published in the Annals of Internal Medicine co-authored
by CHS Associate Investigator Karen
Sherman, PhD, MPH. Participants were randomized to receive one of the
following four treatments: 1) an acupuncture program specifically designed
to treat fibromyalgia; 2) acupuncture for an unrelated condition; 3) needle
insertion at nonacupoint locations; or 4) noninsertive simulated
acupuncture. After receiving twice-weekly treatments for 12 weeks, subjects
receiving acupuncture for fibromyalgia did not report better average pain
ratings than did participants in the other three sham acupuncture groups
combined.
Having diabetes is a strong risk factor for sudden cardiac death,
according to a study of nearly 6,000 Group Health patients that was
published in the June 24, 2005 online edition of the European Heart
Journal. Researchers from the University of Washington’s Cardiovascular
Health Research Unit joined lead author Xavier Jouven, MD, PhD, of the
University of Paris to conduct the study, which compared the cases of
patients in four groups: 1) no diabetes, 2) borderline diabetes, 3) diabetes
without microvascular disease, and 4) diabetes with microvascular disease.
They found that when compared to no diabetes, there was a progressively
higher risk of sudden cardiac death linked to borderline diabetes, diabetes
without microvascular disease, and diabetes with microvascular disease. High
glucose levels were also associated with the risk of sudden cardiac death
both in the absence and presence of microvascular disease.
Quality improvement collaboratives are a useful method to foster
change in chronic care settings, according to an article co-authored by
CHS Research Associates Judith
Schaefer, PhD, and Amy Bonomi, PhD, MPH. The pair joined researchers
from the RAND Corporation, the University of California, Berkeley, and Johns
Hopkins University, to publish the article titled "Assessing the
Implementation of the Chronic Care Model in Quality Improvement
Collaboratives" in the August 2005 issue of Health Services Research.
The article shows that learning sessions conducted by Improving Chronic
Illness Care (a research project managed by CHS’ MacColl Institute) and the
Institute for Healthcare Improvement allowed 42 health care organizations to
implement large numbers of quality–improvement (QI) change strategies
associated with the Chronic Care Model.
It’s feasible to develop systems for faster and more routine
population-based assessments of new vaccine safety, according to a study
led by CHS Senior Investigator Robert L. Davis, MD, MPH, and published in
the May 2005 issue of the journal Epidemiology. The study used
historical data from the introduction of two vaccines in the 1990s to test
an innovative "active surveillance" method that can quickly compare outcomes
in large populations of people who receive a new vaccine to those who do not
receive it. The study showed that the method allows the researchers to
accurately detect rare adverse events within weeks following the initiation
of a new vaccine program. While this study outlined how this system could
work with vaccine, Davis is also working on extending such a system to
perform active surveillance for newly introduced medications.
Physicians can do a better job of delivering anti-smoking messages to
pre-teens, according to a study in the April 2005 Journal of
Pediatric Psychology. Led by Free & Clear Chief Medical Officer and CHS
Affiliate Investigator Tim McAfee, MD, MPH, the study found that less than
25 percent of pre-teens and their parents surveyed could recall tobacco
prevention messages delivered by health care providers. Recall of
anti-smoking messages at school (68 percent), from parents (53 percent), and
from the mass media (71 percent) was higher. CHS researchers on the study,
which was conducted at Group Health and Kaiser Permanente Northwest,
included Evette Ludman, PhD,
Lou Grothaus, MA, and Terry Bush,
PhD. Free & Clear’s Sue Zbikowski, PhD, a CHS affiliate investigator, also
contributed.
The best proven approaches to improving public health are explored
in a new book by the U.S. Task Force on Community Preventive Services, a
22-member panel that includes CHS Senior Investigator
Robert S. "Tom" Thompson, MD.
Titled The Guide to Community Preventive Services: What Works to Promote
Health (Oxford Press, 2005), the 500-page book recommends
community-based interventions to address problems such as tobacco use,
physical inactivity, violence, cancer, diabetes, vaccine-preventable
disease, and motor vehicle injuries.
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