Fig. 4. Graph showing the correlation between referral rate to HES and the percentage of optometrists who hold the IP qualification for each health board in 2018/2019.

For all 14 health boards (solid trendline), the Pearson correlation was not significant, r = +0.53, 95% CI −0.002 to 0.83, p = 0.052. Excluding the three health boards with no IP optometrists (dashed trendline), Pearson correlation was r = −0.06, 95% CI −0.64 to 0.56, p = 0.86 (still not significant).