actual vs theoretical

This month has been a very interesting month that has centered around theoretical vs actual. The month started with budget estimates and how many students we can screen. The discussion degenerated into how much theoretically can you do and how much do you expect to do. Theoretically we can do a significant number of ECGs. Our average tech can perform one screening every three to five minutes. If we assume five minutes we can do twenty ECGs per hour. Given that there are about five hours per day that we can screen during the school day and two after hours, one person can screen 140 students per day. Granted, that is a long day of standing and screening students. We usually being more people and machines to reduce the wait time and compress the screening into shorter hours. Given that we have about 20 machines our theoretical limit would be 2800 students per day. This brings us back to theoretical and actual. The largest screening we had in one day was 350. We had six machines and screeners for six hours. Even though we can do about 3000 per day, 300 is a more realistic number. If we look at it closer we didn't do that many more than a handful of times throughout the year. A number closer to 100-200 per day is a typical day. Given that we have about 180 days that kids are in school we should be able to screen 504,000. Again, that isn't practical. If we want to target screening 20,000 students and assume that we can screen about every other day on average we need to screen about 220 students at an average screening and do that about 100 times a year. Not only is this number practical but it is realistic. We can fill in some Saturdays or after school as well as extend into late summer during pre-season. Screening 20,000 students is not only theoretically possible but is in line with numbers we have generated in the past and maintained over longer periods.

A recent article in the American Heart Circulation (May 29, 2012, Volume 125, Issue 21) also generated significant discussion earlier this month. The article from Tufts University talks about the cost effectiveness of screening high school students using simulation models and assumptions drawn from existing literature. The simulation shows that the cost per life-year saved ranges from $91,000 to $204,000. Given that we screen students and follow what actually happens to them we decided to compare the theoretical against actual. We have screened just over 20,000 students and cleared 95% of them with an ECG test that we charge $15 per student. If you assume that a follow up exam is $300 for a doctor visit and limited echo and $900 for someone flagged as high risk, the cost of screening comes out to $300K for healthy patients, $268K for follow up patients and $39.6K for high risk patients. If you further assume that 80% of all high risk and follow up patients are cleared and can be treated with medication, the remaining 20% represent an additional cost of $357K of treatment with continued care and long term medication and $352K for surgical correction (9 students at $40K per surgery). Two of the high risk students had heart transplants at a cost of $1.5M each.

Our actual numbers show that screening 20,000 students cost $300K with the burden being on the parents who wanted screening. The remaining $268K and $39.6K was split by the insurance companies and the parents. For the 18 students that have heart issues that do not require surgery but have heart issues the $107K cost is split by the insurance companies and parents. For the 11 students that had corrective surgery the $352K for minor surgeries and $3M for heart transplants were effectively paid for by insurance.

If we include the two students that had heart transplants the cost per life saved for the program is $388K. If we assume that the 11 that had surgery would have died before they were 30 and they will now live to be 75, the cost per life-year saved is $8,600 (dividing 388K by 45 years of additional life). If we drop out the two heart transplants the cost per life saved is $150K or $3.3K per life-year saved assuming that the 9 students live an additional 45 years due to the surgery. If we assume that the student lives an additional ten years this still results in $38K per life-year saved and $15K per life-year saved without the heart transplants.

Actual vs theoretical is a good discussion. When we are talking about actual lives saved and actual screening of students, simulations and extrapolations are not good enough. Having 11 kids that have gone through surgery, two major and nine minor, and 179 that have heart issues that are being treated early in their lives can not be ignored. Ask any of these 190 students if they think that screening is worthwhile and I think that every one of them and their parents will say yes. We can talk about life years saved and was a life saved or did we just postpone something but improving the lives of these 190 students is significant. Confirming that the remaining 19,810 students don't have heart problems is equally significant. Our stance is that affordable screening works. Eight years of screening with confirmation from multiple Cardiologists that the 190 students that have gone through this program and been identified as someone with a heart issue that needs treatment can not be discounted despite what a simulator or extrapolation from other publications tells you.