The Manitoba Cataract Waiting List Program

Dear Editor:

Bellan et al. (CMAJ 2001;164(8):1177-80) present data on the Manitoba Cataract Waiting List Program (MCWLP) which represents the first attempt to institute standard priorization criteria in a Canadian context for cataract surgery. While this is a worthwhile effort to manage waiting lists, we have a few concerns regarding the scoring system used for priorization.

The VF-14 questionnaire is already heavily biased towards working and driving. The addition of 60 extra points for work and driving impairment alters the point scoring significantly and has not been validated in outcome studies. The fact that a correlation developed between VF-14 scores, and difficulty with work or driving following institution of the system proves surgeon use of the system to priorize their patients. However, unless objective patient derived outcome measures are used to show that patients with high priority scores also have better visual function outcomes or less morbidity while waiting for surgery, it does not prove that the correct patients have been priorized for surgery. The ultimate goal of priorizing waiting lists (rather than simply using first-come, first-served) is to reduce morbidity (and mortality) of patients waiting for surgery. Until this is achieved, the MCWLP is only a consensus model to which this group of surgeons has agreed.

The use of an open ended priority score with points given for waiting also defeats the objective of equitable treatment and encourages surgeon manipulation of the system. In many parts of Canada where 12-18 month waits for surgery are commonplace, the mere act of waiting for 18 months would give a patient a higher priority score than someone who had much more severe visual morbidity. The act of waiting should only increase priority if there is worsening of the clinical condition or there is clearly proven morbidity while waiting. Otherwise, waiting for surgery without deterioration is a success of medical therapy rather than a failure of surgical therapy. Ultimately, this turns the system into a pure waiting time based system in areas with long waits. It also encourages surgeons to put patients on waiting lists before they require surgery, causing a downward creep in the threshold for surgery.

Although the instrument described is very useful in alerting individual surgeons to patients who may need accelerated surgery, we do not feel the priority system used in the MCWLP will be useful for priorizing patients across surgeons or allocating operating room resources for the above reasons.

Suren Sanmugasunderam
University of British Columbia
Vancouver, BC

Ken Romanchuk
University of Saskatchewan
Saskatoon, Saskatchewan