Assessment and improvement of figures to visually convey benefit and risk of stroke thrombolysis

Abstract

Background and purpose: Deciding whether to use intravenous fibrinolytic therapy for acute cerebral ischemia within 3 hours of onset is challenging for patients, family members, and health care providers. Visual displays can permit individuals to rapidly understand response patterns to therapy. This study sought to evaluate, refine, and improve existing visual aids for stroke fibrinolytic decision-making.

Methods: Existing visual aids were identified by Medline search and querying of national guideline organizations, pharmaceutical manufacturers, and stroke specialists, and were rated on a formal 8-point quality rating scale (0, lowest; 8, highest). Based on available instruments, new visual displays were developed to improve informed decision-making in routine practice.

Results: Two existing visual aids were identified, one from an emergency medicine society and one from a pharmaceutical company. Both were comparison visual displays of outcomes with and without treatment; no decision matrix visual aid was found. Both scored 4.0 on the quality scale, showing defects of effect size distortion, privileging less salient outcomes, dissimilar representation by treatment group, and limited stakeholder participation in generation. Revised versions of these graphics were developed with higher quality scores (6.75 and 7.75). In addition, a new decision matrix display with quality score 8.0 was developed that complements the numeric text of a national patient education tool developed jointly by US neurology, emergency medicine, and stroke patient organizations.

Conclusions: Existing visual aids for stroke fibrinolysis decision-making have deficiencies. New visual displays are now available to convey the health benefits and risks of fibrinolytic stroke therapy efficiently and informatively to patients and family members.

Figure 1

A) Left figure from an emergency medicine society shows defects of effect size distortion, privileging less salient outcomes, and dissimilar representation by treatment group. B) In Right figure, replacement of the black circle with a red double minus circle corrects the privileging of less salient outcomes and dissimilar representation by treatment group. However, the effect size distortion is not corrected. (Figure published with permission of UCLA Stroke Center.)

Figure 2

A) Top figure from a pharmaceutical company show defects of effect size distortion, privileging less salient outcomes, and dissimilar representation by treatment group. B) In Bottom figure, recoloring of person-icons and basing graphic on actual, rather than imputed, disability measures reduces the effect size distortion and corrects the privileging of less salient outcomes and dissimilar representation by treatment group. (Figure published with permission of UCLA Stroke Center.)

Figure 3

Decision matrix figure illustrating the benefits and risks of IV TPA in the under 3 hour window based upon data from the two NINDS-TPA trials. (Figure published with permission of UCLA Stroke Center.)