Provide longitudinal PRO information

In many cases, PRO data from a single point in time may not be sufficient to support patient-provider communication or decision-making. Monitoring PROs over time provides a broader view of a patient’s health status that can facilitate timely intervention and inform future expectations as well as enhance follow-up care. Longitudinal visualizations of PROs provide a means to capture the progress of signs, symptoms, and outcomes in ePRO reports.

Strategy A
Represent PRO data collected over time in longitudinal visualizations to improve its clinical usefulness

Longitudinal visualizations (e.g., graphs, tables) enable providers to view patient status as reported through ePROs both as a specific point in time and as part of a trend. ePROs collected over time enable providers to trend PRO scores for a more holistic view of patient health. Longitudinal graphs and tables can be an effective means to illustrate patient trends and inform trajectory expectations. Longitudinal PRO data from one patient may also be valuable for comparing individual patient trends with trends from a reference population.

Representing longitudinal information can take many forms. Figure 4D (i–v) provides examples of how longitudinal information can be presented.

Quote from Provider Interviews:

“It would be interesting for me to see [PRO data from] somebody from the time that I first started treating them…to really get an idea of how things are changing…if you've been seeing somebody for ten years and their pain score has been the exact same the entire ten years, to me, that gives you a lot of information about what to expect.”

Figure 4D (i–v): Examples of presenting patient longitudinal trends

Figure 4D (i). ePRO Longitudinal Points

Graphic showing a patient's mean disability score over time as points, from pre-treatment, to 60 days, to 1 year, finally to 2 years.

Figure 4D (ii). ePRO Longitudinal Line Graph

Graphic showing a patient's back pain score over time as a line graph, from July 2018, to October 2018, to January 2019, finally to April 2019.

Figure 4D (iii). ePRO Longitudinal Vertical Bar Graph

Graphic showing a patient's back pain score over time as a bar graph, with a bar at several places indicating the month/year of a PRO assessment.

Figure 4D (iv). ePRO Longitudinal Table

Graphic showing a patient's back pain score over time as a table, showing the score, mean score, and range at three points in time.

Figure 4D (v). PRO Longitudinal Color Bar

Graphic showing a patient's disability score as two colored bar graphs, with a bar for 60 days ago and one for today.

Table 4B lists factors to consider when providing PRO data longitudinally for provider use.

Table 4B: Strategy considerations for providing PRO longitudinal data
Strategy Consideration PRO Tips
Time spans and intervals to display
  • May align with treatments, clinical benchmarks, or office visit schedules
  • May vary by condition and clinical specialty
  • Seem to provide easier orientation to the PRO timeline when axis labels use calendar dates rather than time from intervention
  • Should be represented with proportional and consistent scaling to accurately reflect time between data points
Representing missing data
  • Can impact visual representations of trends and complicate interpretation. The impact may be mitigated when there is a clear, visual annotation regarding missing data.
Pre/post intervention status
  • Aids in clinical decision-making and helps providers communicate with patients about change in status over time
  • Should clearly indicate whether the PRO was collected prior to or following an intervention
Trend lines
  • Show high level trends and generalities rather than precise representations of every change in patient status
  • Can serve as a comparison to aid interpretation of individual patient scores

Some of the prevailing challenges for operationalizing the strategy are listed below, along with tactics to consider in addressing these challenges:

Challenges and Tactics Longitudinal Information


  • Partial Story: Longitudinal displays may not tell the entire patient story.
  • Trend line imprecision: Connecting lines between measurement points may not provide a precise depiction of patient changes (especially when there are long intervals between measurement).


  • Provide access to additional contextual information (e.g., additional clinical data) to support patient-provider communication and decision-making.
  • Use caution when interpreting the significance of trends and changes in scores over time.

For additional insight on how to present longitudinal data on ePRO reports, see the Toolkit Resources related to: