Thanks for going over this. I'm a busy primary care pediatrician, and appreciate your analysis. I read this paper carefully yesterday. It's helpful to know I'm interpreting it correctly. I agree with you that it will be important to have long term data on impact after 2-3 seasons. I've heard pediatricians say that treated babies get RSV too, just don't get as sick, so they'll be the same as untreated babies the next season, but we don't know that to be true.
Based on this study, nirsevimab ONLY shows statistically significant efficacy in infants <3 mo, right?
I'm glad you focused on absolute risk reduction rather than relative risk reduction. I would have liked to see more information on the hospitalized children, and I'm guessing that's not provided because it doesn't help make the case for using this product universally. It was included in the previously published trial. In the context of our practice, it's very unusual for a child to be admitted for RSV LRTI unless they need supplemental O2 (very severe definition). In the previous trial, average length of stay was 2-4 days. I would guess the ones who were admitted for "not very severe" RSV had shorter stays overall, just admitted overnight for observation, or were admitted for something else. Wish I knew for sure.
NNT info is important to consider, I think the number is 288 to prevent very severe hospitalizations, right? Cost per dose is about $600 ($495 from vendor plus costs to administer). That would be $172800 to prevent one of those hospitalizations.
I'm particularly interested in this now because there have been shortages of the product, so it wasn't as widely used as expected. The shortages are now relieved, and CDC announced last Friday that pediatricians should be urgently getting this into all infants <8 mo. We're on the downslope of the RSV season for this winter, nationally and in my region (midwest). The efficacy of this product is obviously diminished when provided late in the RSV season since it won't last till next year, so we can assume that NNT and cost per episode prevented would be even more unfavorable.
I think this product will turn out to have some real value, especially for younger infants and those with vulnerabilities. But this is another example of regulatory agencies more interested in supporting sales of a product than thinking about it carefully. And that really bugs me. I hope a lot of people read your analysis. Thanks again!
Thank you so much for the kind response! I'm happy to hear it was valuable to you. With respect to the specific claim about only being statistically significant in infants <3 months, that is true, but I don't believe they were technically powered to detect a difference in each subgroup, so we can't assume it wouldn't have been statistically significant in larger numbers.
I agree with your concerns, and pushing to all infants under 8 months seems ridiculous. I'm sure it's been a busy season, hope all is well!
Dave-
Thanks for going over this. I'm a busy primary care pediatrician, and appreciate your analysis. I read this paper carefully yesterday. It's helpful to know I'm interpreting it correctly. I agree with you that it will be important to have long term data on impact after 2-3 seasons. I've heard pediatricians say that treated babies get RSV too, just don't get as sick, so they'll be the same as untreated babies the next season, but we don't know that to be true.
Based on this study, nirsevimab ONLY shows statistically significant efficacy in infants <3 mo, right?
I'm glad you focused on absolute risk reduction rather than relative risk reduction. I would have liked to see more information on the hospitalized children, and I'm guessing that's not provided because it doesn't help make the case for using this product universally. It was included in the previously published trial. In the context of our practice, it's very unusual for a child to be admitted for RSV LRTI unless they need supplemental O2 (very severe definition). In the previous trial, average length of stay was 2-4 days. I would guess the ones who were admitted for "not very severe" RSV had shorter stays overall, just admitted overnight for observation, or were admitted for something else. Wish I knew for sure.
NNT info is important to consider, I think the number is 288 to prevent very severe hospitalizations, right? Cost per dose is about $600 ($495 from vendor plus costs to administer). That would be $172800 to prevent one of those hospitalizations.
I'm particularly interested in this now because there have been shortages of the product, so it wasn't as widely used as expected. The shortages are now relieved, and CDC announced last Friday that pediatricians should be urgently getting this into all infants <8 mo. We're on the downslope of the RSV season for this winter, nationally and in my region (midwest). The efficacy of this product is obviously diminished when provided late in the RSV season since it won't last till next year, so we can assume that NNT and cost per episode prevented would be even more unfavorable.
I think this product will turn out to have some real value, especially for younger infants and those with vulnerabilities. But this is another example of regulatory agencies more interested in supporting sales of a product than thinking about it carefully. And that really bugs me. I hope a lot of people read your analysis. Thanks again!
Thank you so much for the kind response! I'm happy to hear it was valuable to you. With respect to the specific claim about only being statistically significant in infants <3 months, that is true, but I don't believe they were technically powered to detect a difference in each subgroup, so we can't assume it wouldn't have been statistically significant in larger numbers.
I agree with your concerns, and pushing to all infants under 8 months seems ridiculous. I'm sure it's been a busy season, hope all is well!