

Editor: Neil B. Gailmard, OD, MBA, FAAO




Your Eyeglass Rx Retention Rate

July 3, 2013


Do you know your eyeglass Rx retention rate? I don't just mean a wild guess; I mean do you actually measure it? It could be one of the most important metrics you have, yet the vast majority of optometrists don't measure it. Or if they do, they base it on the total number of refractions (or exams) divided by the total number of eyeglasses sold. That method is easy because the data comes right from your office management software reports, but it is not very accurate. We all know that there are many refractions performed that do not result in a spectacle prescription in the first place. We do refractions all the time as part of comprehensive eye exams, but there may be no prescription change or we may find the patient to be emmetropic. How can you expect to sell a pair of glasses when there was no Rx?
Tracking the true eyeglass capture rate is pretty easy, but it takes a system. Read on for a very good method.
Track the walkout number
In order to track the Rx retention percentage, it is easiest to count the prescriptions that actually walk out. This is a smaller number to count than those who fill their Rx for glasses with your office (at least I hope so!). The Rx retention rate is simply the inverse of the Rx walkout rate, so if you count one, you know the other. Your staff generally knows exactly which patients are taking their eyeglass Rx with the intention of buying glasses elsewhere.
You can review your office procedures to refine this any way you wish, but if the patient buys glasses from your practice and wants a copy of the Rx for his records, I do not count that as a walkout. If he wants a prescription for safety glasses which are provided by his employer, I don't count that either. If I recommend a new prescription and the patient does not buy glasses but wants a copy of the Rx, I count that as a walkout. There is some judgment, but your staff can be pretty accurate about the patient's intent.
Train your staff to always print two copies of the Rx in these cases where the patient is walking with it; or you could write it on spectacle Rx blanks made with twopart paper. Give one copy to the patient and drop the other copy in a tray or a box. At the end of every month, count the Rx copies that went elsewhere.
Convert to a rate
The rest is easy, but there is a bit more to it than you might think. We need the number of eyeglass prescriptions written for the month. Count the total number of eyeglass orders you had for the month. I count pairs of lenses sold. But you have to also add the ones that walked out to get the total!
Technically my "pairs of lenses" sold includes outside Rxs that walked in and it includes multiple pair sales to the same patient. Those should be factored out to be truly accurate. Some practices just let the walkins cancel some of the walkouts; that is up to you.
Divide the total number of walkout Rxs by the total number of Rxs as determined above and you have the walkout Rx rate as a percentage. Let's say you made 220 pairs of glasses and had 28 walkout Rxs last month. Your total Rxs was 248. Divide 28 by 248 and you get 11.29% or round off to an 11% walkout rate.
The retention rate or capture rate is the more positive way to look at this statistic, which is simply the difference needed to make 100%. Your Rx retention rate was 89% for the month in our example.
A spreadsheet
The simple math involved in these calculations can easily be programmed into a spreadsheet with the following cells:
 Total number of Rxs sold per month. Lens pairs. Not including walkins and multiple pairs.
 Total number of Rxs walked out per month. Must be managed carefully. Staff must write or print two copies and file one.
 Add A and B for total Rxs written.
 Divide B by C X 100 for Rx walkout %.
 100 – D for Rx retention %.
Your staff can simply plug the numbers into cells A and B and the math is carried through. You now have a monthly record for future comparison.
How does it help?
Many management decisions can be aided by this important metric.
 You might try raising fees and seeing if it has an adverse effect on the retention rate. And how big of an effect? Did you still net more income?
 You could try a better eyeglass warranty or no warranty and see if it matters.
 You could see if your retention is better with the use of scribes who can also measure and dispense eyewear.
 You can try different scripts for your staff.
 You can test lens and frame packages or a new budget frame line and see if retention improves.
 You can look at the absolute value of the retention rate and make a management decision that it could be better. This may be determined by comparing your rate with colleagues or national data. In the end, you could decide to improve your optical by making it larger or remodeling it and then track the improvement in retention rate.

