Flu Report: Providers Prescribing Antivirals at Higher Rate

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Earlier this week, we reported on the current rates of influenza-like illness (ILI), based on data from roughly one million patient visits on the athenahealth network. That report showed a steep increase in ILI rates for the week ending Saturday, December 13 (see previous post). It’s not certain that this season will be as severe as that of 2012-2013 (data for pediatrics suggests that is a real possibility); however, providers are testing for flu more consistently than previous years, and prescribing antivirals more often.

Our data shows that the number of flu tests ordered, per patient visit in which ILI is diagnosed, has risen each of the past two years (Figure 1, graph A). This season, providers are ordering flu tests at a rate of 0.53 tests per visit with an ILI diagnosis, compared to 0.37 for last season and 0.34 for 2012-2013. (Note: There can be multiple tests per patient visit, e.g. Type A and B.)

Providers are also more likely to prescribe antivirals for ILI this flu season, compared to the past two seasons (Figure 1, graph B). This is likely a result of the increased number of tests, as well as the CDC issued advisory recommending the prescription of antivirals this season to reduce flu symptoms.

This combination of an increase in flu tests and an increase in prescriptions for antivirals suggests that health care providers have become more proactive about treating the flu. One reason could be a fundamental change in providers’ approach to flu, after the severe season of 2012-2013. An alternative explanation is that providers are aware of, and are responding to, one of this season’s flu strains (H3N2), the same strain that was predominant two seasons ago.


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Given the increase in both ILI rates and flu treatment activity, we would not be surprised if this season has yet to peak. With next week’s flu update, we’ll provide state level maps, which we hope will be helpful as people embark on Christmas travel.

Iyue Sung, PhD is the Director of the athenaresearch unit. 

As always, your comments and suggestions are welcome and may be directed to athenaresearch@athenahealth.com, or to @IyueSung or@JoshGray_HIT on Twitter.

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8 replies »

  1. Hi Al,

    Thanks for the compliment!

    We really do think our data has value and utility for the general public.

    We think we’re just scratching the surface on its potential, and disease surveillance seems like a good and useful place to start.

    And we’re always open to suggestions as well.


  2. Hi John,

    Agreed – that would be very interesting!

    We do have our vaccination and ILI data at various geographic levels. So if you’re aware of another data source that would have information on refusal rates by, say… zip, county, or state, we could certainly see if there’s an association.


  3. This is a great example of how one company — a very successful one — is using big data and gaining real-time insights from it. Not too long ago, we wouldn’t have learned this until well after the point when we could have benefited from knowing it.

    The CDC can look at this and realize that their advisories worked, whereas if the reverse were true, they could recalibrate and send out new advisories. Providers of antivirals can use this to estimate future demand and optimize inventory levels, which is good for them but also for us because it prevents shortages and also potentially going out of code.

    Kudos to Athena. This is even better than they think — I don’t think they realize the significance of this find in the bigger picture.

  4. You’ve got me thinking.

    Vaccinations. Anti-vaxxers. Hmm ..

    It would be fascinating to do a compare and contrast on refusal rates for different areas of the country. I’d also be interested to see how those numbers are trending over time .. Has the anti-vaxxer movement peaked? Is it stronger in some areas of the coutnry? Is it losing strength in others?

  5. Hi LUFH,

    Thanks for your comment.

    It’s very plausible that Ebola has increased overall vigilance around communicable diseases.

    We looked at flu test and antiviral prescription rates by census region (not shown), and the Midwest, South and West (but not Northeast), shows similar spikes.

    So if the Ebola hypothesis is correct, it would suggest a national effect.

    We do have the ability to look at fevers, but did not do so here. Thank you for your suggestion!


  6. Cool idea guys.

    We should see how these numbers compare with Google Flu Trends.

    Have you looked at that in the past?

  7. I bet this is partly the E word.

    As in, Ebola.

    Would be interesting to look at numbers in New York City and Texas in isolation

    Do you have any data on “Ebola-like” symptoms – “foreign travel” queries.. ?

    Do you have the ability to look at the number of patients with 102 degree fevers and above ..

    That would be interesting