Do waiting times really matter?

Short abstract

Shortening the waiting time for cataract surgery improves patients' quality of life

Mojon‐Azzi and Mojon¹ have performed a superb analysis (see pages 282) which demonstrates that the waiting time for cataract surgery in 10 European countries is influenced primarily by the total expenditure on health (p<0.01). Of note is the fact that public expenditure on health, physician density and acute hospital bed density did not significantly influence waiting times.

Since cataract waiting times differ significantly among countries (p<0.001), a reasonable question to ask is, “do waiting times really make a difference for the average patient?”. Fortunately, a value‐based medicine analysis sheds some light on this issue.

Excellent evidence‐based data come from the PORT study, in which the average person who underwent cataract surgery had a visual acuity of 20/83 in the affected eye.²,³ The average postoperative visual acuity, factoring in the complications of posterior capsular opacification, endophthalmitis, loss of lens particles into the vitreous cavity, intraocular lens dislocation, retinal detachment, cystoid macular oedema and bullous keratopathy, was 20/27.³

Utility values allow us to reproducibly quantify the quality of life associated with a health state.⁴ Utilities also allow us to calculate the total value (improvement in quality of life and length of life) conferred by virtually all interventions. For ocular procedures, the value gain is typically conferred by improvement in quality of life rather than improvement in length of life.

With vision, utility values decrease as the corresponding visual acuity in the better‐seeing eye decreases.⁴ Assuming that patients undergoing surgery have cataracts that are equal in both eyes, the utility value associated with 20/83 vision preoperatively is 0.71 and the utility value associated with 20/27 vision postoperatively is 0.858.³ This results in a 0.148 (0.858−0.71) utility gain conferred by the cataract surgery.

The mean age of SHARE patients waiting for cataract surgery was 73.8 years.¹ The average life expectancy for a person of this age is approximately 13 years.⁵,⁶

The mean waiting time in the SHARE study was 3.3 months, but the wait to see an ophthalmologist can be up to a year.¹ Therefore, a total of 15.3 months could be necessary from the time a patient notes disabling visual loss until the responsible cataract is removed.

To calculate the quality of life lost in this instance (in quality‐adjusted life‐years, QALYs)³,⁴ by delaying cataract surgery, the utility gain conferred by cataract surgery is multiplied by the time (in years) from visual loss until the cataract is removed. Thus, there is a (0.148 utility gain×1.275 years) = 0.19 QALY gain.

Looked at in another way, the average patient waiting 15.3 months for cataract surgery has a 21% diminution in quality of life, or life's value, during this time. This is a dramatic diminution in quality‐of‐life, equivalent to having an amputation versus no amputation or having clinically relevant coronary artery disease versus having none.⁷ Averaged over the remaining lifetime of the patient, the 15.3 month wait for surgery results in a 1.6% diminution in quality of life on a daily basis. This latter percentage is not as severe as the diminution during the waiting period but is still considerable when it occurs only secondary to waiting!

In essence, the quality of life associated with various health states includes more than just what happens on the days of surgery or another intervention. As healthcare providers, we should do our best to maximise the value we confer to our patients. Shortening the waiting time from the start of visual disability until the responsible cataract is removed, or alternatively the waiting time for many other healthcare interventions, is a good way to begin.