Readability of "Dear Patient" device advisory notification letters created by a device manufacturer

In 2006, the Heart Rhythm Society (HRS) recommended that cardiovascular implantable electronic device (CIED) manufacturers use advisory notification letters to communicate with affected patients.

To evaluate the readability of the HRS sample "patient device advisory notification" letter and those created by 1 CIED manufacturer.

The HRS sample letter and 25 Boston Scientific Corporation letters dated from 2005 through 2011 were evaluated by using 6 readability tests.

Readability (Flesch-Kincaid score) of the HRS sample letter was grade level 12.5, and median readability of the device manufacturer letters was grade level 12.8 (range 10.8-18.9). Similar results were obtained by using other readability scales. No letters had readability scores at the National Work Group on Literacy and Health's recommended reading level-fifth grade; the letters' readability exceeded this recommended level by an average of 7.7 grades (95% confidence interval 6.9-8.5; P<.001). Likewise, no letters had readability scores at the average reading level of US adults-eighth grade; the letters' readability exceeded this level by an average of 4.7 grades (95% confidence interval 3.9-5.5; P< .001).

The readability of the HRS sample letter and those created by a CIED manufacturer significantly exceeded the recommended and average US adults' reading skill levels. Such letters are unlikely to be informative to many patients. CIED manufacturers should ensure that advisory letters are comprehensible to most affected patients.