Economic Burden of OIC Management

William F. Peacock, MD: We did a fairly sophisticated analysis of a large database of hospitalized patients to see the economic outcome of using a PAMORA, a peripheral acting μ-receptor antagonist. In our analysis, methylnaltrexone was the most common, about 93%, but that’s just a marketplace function. We did this analysis to find out how it worked and what the economic consequences of it were. It was a health economics analysis. We took about 30,000 patients, and we did what’s called an entropy analysis. When you do this, you control for as many as 50 variables. You take the mean and the standard deviation, so that the 2 populations—those who have OIC [opioid-induced constipation] and get a PAMORA and those who don’t get the PAMORA—are matched well. We did that, and we ended up with 20,000 patients in the non-PAMORA group and 10,000 in the PAMORA group. We can compare those populations. It’s a retrospective study full of all the retrospective study concerns and limitations, but the matching process takes us into a much more sophisticated realm of understanding.

Using that entropy-controlling analysis, we were able to demonstrate that on average, for a person who had OIC and got a PAMORA, the cost savings was about $730 per dose, which is pretty phenomenal. Very few things save money like that. The function is that they stay shorter in the ER [emergency department]. They get the shot. This is a subcutaneous injection, so there’s a pill form, but the pill form isn’t an emergency doctor target. We want somebody to have a relief or not so we can make a decision. I don’t want to wait 4, 5, 6 hours. It’s a subcutaneous injection. The patient has a relief for their symptoms, and you make a decision.

This drug works in an hour or 2. When that happens, you can then decide if you can go home. If I can discharge somebody in 2 or 3 hours in the emergency department, that’s a win, as opposed to messing around with them for 6 or 8 hours. That’s a discharge. There’s huge money saved when you can discharge somebody who wasn’t getting discharged before. So you give a shot, you wait 2 hours, then they can go home. It shortens the ER length of stay; that’s a cost savings. They can go home; that’s a cost savings.

About 60% or 70% of the people who got treatment were able to be discharged, which isn’t our normal game. Historically, most patients with opioid-induced constipation come in the hospital the ER, and we do what we can do. We do manual disimpaction, we give them enemas that don’t work well. They’re not happy, and they end up getting put into observation or hospitalized. This is a way to change the trajectory for that patient. You can do something that works and send them home. That’s why it’s a cost savings of $730 per patient.

Is patient monitor follow-up required? Remember, these are patients with cancer—70% of them had cancer. The answer is yes. Monitoring and follow-up are required, not for the opioid-induced constipation but because of their underlying disease. These are fragile patients who were sick, so they’re going to follow up with their doctor no matter what, even if I don’t do anything. The methylnaltrexone doesn’t create a special scenario of monitoring or follow-up. It’s not necessary. If they had a benefit from their treatment in the emergency department and go home, they can follow up as scheduled regularly with their doctor.

One thing the emergency doctor can consider is whether to put the patient on the oral pill when they leave, and you can do that. They take it every other day, but that’s a decision to be made with the patient at the time of the visit. Once the problem is cured, you can turn that over to their doctor as an outpatient if you wanted.

For people who take narcotics, opioid-induced constipation is 1 of the most common complications. In the patients we were talking about in our analysis, it was the most common reason to come to the emergency department. About 60% of these people ended up with at least 1 visit. Some of that is a function of our analysis. We were looking for people with ER visits so we could study them. What it tells you is that opioid-induced constipation is a common problem, and it results in frequent emergency department visits.

In this study, the large analysis—the 30,000-patient evaluation—most patients are pretty sick. They’re patients who have 70% metastatic cancer, and they’re getting complicated therapies for their underlying disease. Then they’re complicated by opioid-induced constipation. This is important because this is what this population looks like. This isn’t a population of relatively healthy patients. This is the real-world population of everybody who’s coming to the emergency department with opioid-induced constipation.

There are limitations. It’s a retrospective study. As such, we had to match patients as best we could. I’ve talked about that a bit. The downside is it’s that a retrospective study. The upside is that it’s a real-world population. These are the real patients who come to the emergency department with opioid-induced constipation. A challenge in this analysis is that there’s no OIC code. I can’t look at a database and go, “Let’s pull out the OIC patients.” We had to create OIC diagnoses. The way we did that is we found people who came to the emergency department with a diagnosis of constipation or obstipation, for which there are codes, or who had a procedure—a manual disimpaction, or something of that nature, so we could track that in the medical record—and who were on a narcotic sometime in the last 6 months. We had to create the population. Then we had to have those patients who got a PAMORA vs those who didn’t. That’s how we ended up with this analysis, but that’s the big weakness in it. If there were a code, it would have been a lot easier. Without a code, we did the best we could diagnostically. That’s sort of the support as to why we still need a randomized controlled trial of patients who we’re certain of their disease and the treatment that was given.

Transcript Edited for Clarity