Much of the focus in data reporting and quality improvement projects is on which measures to track and for which patients, however, an equally important criterion is which period type to track and understanding the results that choice will yield. Azara DRVS offers four period types for most measures, each with their own benefits and limitations: Year, Trailing Year, Quarter, and Month. One of the keys to maximizing the value of DRVS’s data is an awareness of what the measure results for a given period type are telling you, and what is the proper use case for that specific measure result.
Year: Most measures are written with the expectation that they will be used for the calendar Year reporting period (January 1 thru December 31), and starting here often makes the most sense for performance tracking purposes, but there are some draw backs as well. Denominators will only include patients with a visit in the calendar year, so it suffers from a lack of patients for the first few months of the year. Additionally, there are patients that will follow the spirit, but not the rules of the measure because of the lookback date for a year period. For example, a patient who was screened for depression on December 30, 2016, but had another visit on January 1, 2017, would not be in the numerator for the measure as part of the 2017 period, even though they were screened 2 days ago. Due to these issues, it is best to only use the Year period type for UDS and other calendar year reporting that occurs at the end of the year.
Trailing Year: The Trailing Year period reflects performance for measures with a year long look back from the end of the current month. This resolves many of the issues associated with the Year period, as it provides accurate numbers at any point in the year. With this period type, patients that will be included in the denominator are those with a visit, and whatever other criteria is required, in the past 12 months. The Numerator will also look back at the past 12 months (or designated time frame), so it maintains the intent set out by the year long measure specification. Similar to the year period, the 12-month look back accounts for any seasonal variability in measure results because of patient's sun exposure (Depression), eating habits (A1c), and stress levels (BP) by including data from all months of the year. 
The main limitation in looking at Trailing Year data is that it will include the past year’s worth of patients (and their performance), so it can take a couple of months for the measure results to reflect changes in workflows, changes in practice, staffing, or outreach efforts. Another implication of this is that there will be patients that are in the numerator of the measure for the Trailing Year period due to data from the previous calendar year, but they will not be in the numerator by the current calendar year. We at Azara consider the Trailing Year period the most versatile of the period types and encourage our clients to use this for monitoring their overall performance on quality improvement measures. However, it is important to understand the above-mentioned caveats and limitations.
Quarter: Measure results from the quarter period type are calculated by including only patients with a visit, and other denominator criteria such as diagnoses or age, in the quarter. Though most measures work as you would expect them to with the quarter period type (same intent, but narrowed in on patients with a visit in the quarter), there are a few measures that provide misleading results with the Quarter period type. Childhood Immunizations is a notable example of this, as the various denominator requirements causes performance to hinge on only a handful of patients at a time when looked at for less than a year’s worth of patients. For the Quarter period type, this happens because the measure denominator will include only patients with both a visit and a 2nd birthday in the quarter (for more on why, read the Age Ranges blog post). Therefore, the primary use of the Quarter period type would be to report measure performance were requested by grant or other compliance programs and to show change over a three-month horizon. Knowing that not all measures work well in this context is important.
Month: The Month period is going to provide performance measures for an even smaller set of patients. Though the same standard of care is applied (e.g., depression screening in the past year) as with a year-long period, it will only include patients that had a visit in the specified month. This can be very helpful when trying to evaluate the impact of a new program (addition of care managers), an equipment purchase (A1c or lead screen point of care device), or workflow changes (referral management or colon cancer screening initiative) as part of a PDSA cycle. Performance will be reflective of only those patients seen in the month and performance will not be degraded or ‘brought down’ by patients seen prior to the start of the change. When rolling out new tools like the DRVS Visit Planning Report, the Month period type will be especially useful in highlighting the changes in performance that comes from reducing missed opportunities. Unfortunately, the Month period type does have the same issues as Quarter period type, and not all measures work the way you might expect with it, so denominators can shrink. In general, the Month period type is best used when trying to see the short-term impact of changes within measure results, and is a useful tool in PDSA cycles and Visit Planning roll-outs.
As the end of the year quickly approaches, the need to identify measures that are not on track to meet 2017’s quality goals becomes even more important. Checking measure performance regularly during the year is the way to ensure that areas needing improvement get the resources and attention they need, within a timeframe that can still impact the reporting period results. Knowing what the measure result for a given period type is telling you, and when is the right time to use that measure result, is key to getting the most out of Azara DRVS and the information it provides.