Johns Hopkins researchers track flu through Twitter
BALTIMORE — "Too sick to go to work, but not sick enough not to tweet about it" Twitter users are helping to predict flu trends. Johns Hopkins researchers recently created a Twitter search method that helps differentiate between people merely tweeting about the flu in general and those who are actually sick, the university announced Thursday. The new tweet-screening method not only delivers real-time data on flu cases, but also filters out online chatter that is not linked to actual flu infections.
Comparing their method, which is based on analysis of 5,000 publicly available tweets per minute, to other Twitter-based tracking tools, the Johns Hopkins researchers reported their real-time results track more closely with government disease data that takes much longer to compile.
“When you look at Twitter posts, you can see people talking about being afraid of catching the flu or asking friends if they should get a flu shot or mentioning a public figure who seems to be ill,” stated Mark Dredze, an assistant research professor in the Department of Computer Science who uses tweets to monitor public health trends. “But posts like this don’t measure how many people have actually contracted the flu. We wanted to separate hype about the flu from messages from people who truly become ill.”
Dredze, who also is a research scientist at the Johns Hopkins Human Language Technology Center of Excellence, led a team that in mid-2011 released one of the first and most comprehensive studies showing that Twitter data can yield useful public health information. Since then, the U.S. Department of Health and Human Services last summer sponsored a contest challenging researchers to design an online application that could track major disease outbreaks.
This winter, as the United States entered an unusually severe and early flu season, Twitter-based flu projections have drawn increasing attention. Many public tweets, such as, “I’m so sick this week with the flu,” can indicate a rise in the flu rate. Collecting enough of these tweets can help health officials gauge the scope and severity of an epidemic.
But the reliability of many computer models can be weakened by too many tweets that point to flu-related news reports and other matters not directly linked to a flu case, according to David Broniatowski, a School of Medicine postdoctoral fellow in the Department of Emergency Medicine’s Center for Advanced Modeling in the Social, Behavioral and Health Sciences. “For example,” he said, “a recent spike in Twitter flu activity was caused by discussions about basketball legend Kobe Bryant’s flu-like symptoms during a recent game. Bryant’s health notwithstanding, such tweets do very little to help public health officials prepare our nation for the next big outbreak.”
To improve their accuracy when using tweets to track the flu, the John Hopkins team developed sophisticated statistical methods based on human language processing technologies. The methods are designed to filter out the chatter. The system can distinguish, for example, between “I have the flu” and “I’m worried about getting the flu."
Another advantage of the Johns Hopkins flu projection method is that it can produce real-time results. By comparison, the U.S. Centers for Disease Control and Prevention, which records flu-related symptoms from hospital visits, typically take two weeks to publish data on the flu’s prevalence.
To check the reliability of their enhanced system, the Johns Hopkins researchers recently compared their results to CDC data for the same period. The researchers said that during November and December 2012, their system demonstrated a substantial improvement in tracking with CDC figures as compared with previous Twitter-based tracking methods. “In late December,” Dredze added, “the news media picked up on the flu epidemic, causing a somewhat spurious rise in the rate produced by our Twitter system. But our new algorithm handles this effect much better than other systems, ignoring the spurious spike in tweets.”
The researchers have also used their Twitter data to produce United States maps that document the stark differences between last year’s mild flu season and the much higher incidence of the virus in the winter of 2012-2013.
“This new work demonstrates that Twitter posts can be used to guide public health officials in their response to outbreaks of infectious diseases,” Dredze said. “Our hope is that the new technology can be used track other diseases as well.”
For a video produced by Twitter about Johns Hopkins’ use of tweets to track public health trends, click here.
CDC: Flu still strong across central U.S.
ATLANTA — If the flu were a storm cloud, the influenza virus is hovering over America’s Bread Basket on its way to the Southwest, according to data provided through the U.S. Outpatient Influenza-like Illness Surveillance Network.
The Centers for Disease Control and Prevention on Friday reported that 4.3% of patient visits reported through ILINet were due to influenza-like illness, above the national baseline of 2.2%. But as the map indicates, influenza rates are declining up and down the East Coast and is most virulent in Texas and states west.
The most hospitalized group affected by this year’s influenza strains are seniors, who account for 50% of reported cases. Among all hospitalizations,87.3% were associated with influenza A 11.9% with influenza B.
For the week ended Jan. 19, 26 states and New York City experienced high ILI activity, down from 30 a week ago. A total of 14 states experienced moderate ILI activity, and nine states experienced low ILI activity. Maine experienced minimal ILI activity.
Merck: FDA approves Oxytrol for Women, creating overactive bladder category in OTC
WHITEHOUSE STATION, N.J. — Merck on Friday announced the Food and Drug Administration has approved the switch of Oxytrol for Women (oxybutynin transdermal system, 3.9 mg/day) from prescription-only to nonprescription, creating a new category — overactive bladder in women — in the OTC area. Most notable about this switch is the fact that the FDA approved Oxytrol for Women against the majority opinion of its Nonprescription Drug Advisory Committee, which voted five in favor and six opposed to the switch in November.
"The approval of Oxytrol for Women as an OTC treatment option is an exciting development for the millions of women who struggle to deal with OAB every day," stated Eman Elkadry, clinical instructor Harvard Medical School; Boston Urogynecology Associates at Mount Auburn Hospital. "This effective, over-the-counter treatment offers women an option to independently manage their condition and achieve a newfound sense of control. The approval also provides recognition that this is a real medical disorder that can be addressed."
Merck anticipates that Oxytrol for Women will be available to customers in the fall.
“When medicines switch from prescription to nonprescription status, consumers benefit from the expanded access and lower cost," observed Scott Melville, president and CEO for the Consumer Healthcare Products Association. "Each year, 240 million people treat their symptoms with over-the-counter medicines, bought off the shelf without a prescription. An estimated 60 million of these consumers would not otherwise seek treatment," he said. "Today’s consumers are taking more control of their healthcare needs, and the FDA’s decision to enhance self-care for women with overactive bladder is a step in the right direction."
Those on the NDAC who voted against the switch cited concerns over the use of therapy for an overactive bladder in women without a doctor’s intervention along with the potential that men might inappropriately choose to use the product as well. These panelists suggested that consumers would have a difficult time self-diagnosing an overactive bladder, as symptoms are similar to those of a number of more serious conditions, such as bladder malignancy or diabetes.
Proponents of the switch argued that women with overactive bladders may go years before consulting a physician and that an OTC option might encourage therapy sooner. The Drug Facts label of the proposed OTC Oxytrol patch included a warning that use should be restricted to two weeks if it doesn’t work.
Overactive bladder, or OAB, is a condition that affects more than 20 million American women. Despite the fact that OAB is a treatable medical condition, more than 80% of women with OAB do not seek treatment. OAB is characterized by a number of symptoms that can be physically burdensome and emotionally draining, including a strong urge to urinate right away and the need to urinate more often than usual, with or without leakage. The majority of women who suffer develop the condition between the ages of 45 and 60 years old.
According to the National Association for Continence, although OAB is a treatable medical condition, most women do not discuss their symptoms with a doctor and assume that the symptoms are a normal part of aging. Rather than seek treatment, many women try to manage their condition with coping strategies that include wearing pads and/or dark clothing, mapping out the nearest toilets and avoiding social interactions outside the home.
The FDA approval of the prescription to OTC switch was based on data from consumer usage studies that demonstrated a woman’s ability to correctly recognize OAB symptoms, understand key safety messages on the label, judge if the product is right or wrong for her and appropriately use Oxytrol for Women in an unsupervised setting. The FDA considers this a partial switch, as Oxytrol will remain available by prescription-only for the treatment of OAB in men. The approval follows an FDA Advisory Committee meeting that occurred in November 2012. Other examples of dual-status medicines include Plan B One Step, which is approved OTC for women older than 16 years but prescription-only for younger women, and Prilosec OTC, which is approved OTC for a frequent heartburn condition but is prescription-only for GERD or for regular use beyond two weeks.
Visit OxytrolForWomen.com for more information.