Oddities in vaccination coverage of US 13-17 year olds as of 2009.

[DarklingAlice]

So the latest edition of MMWR had an article about vaccination rates among adolescents aged 13-17 in the United States. It can be found here. Now picking through this treasure trove of juicy epidemiological data, I came across some numbers that I am at a loss to explain, and would be quite interested in hearing hypotheses on the subject.

1. For MMR (Measles, Mumps, Rubella) coverage there is a discrepancy of 3.9 percent between coverage of white and black populations. However, there is no great discrepancy between populations living below the poverty line and those at or above it (1.5 percent), suggesting that this discrepancy is non-economic in origin (or at least not wholly economic).

2. Individuals living below the poverty line are significantly more likely to have received their first dose of HPV vaccine by a discrepancy of a full 9.4 percent; however, they are not more likely to have completed a full three dose course (discrepancy of 1.3 percent).

In short: What non-poverty related factors could cause a discrepancy in vaccination rate between two racial/ethnic groups? And, what circumstances could account for a higher rate of vaccination among those living below the poverty line?

If you want to present a hypothesis (and I really hope you do, cause I am kind of stumped), please do so with academic rigor and decorum (bonus points for citations ^_^). This is here in EU rather than P&R because I do not intend to invite or tolerate debate of politics. The goal of this is to identify raw epidemiological factors, not to grouse, finger-point, or be partisan. If you wish to support an anti-vac opinion, play the blame game, or bicker, please make your own thread. Thanks.

[Oniya]

I don't intend to put this forward as a pro- or anti-vaccination point, but I know that there was a big to-do about the MMR vaccine, thanks to possibly fallible studies that indicated either a) a connection to autism, or b) a concern with a now-discontinued preservative in vaccines.  It may be possible that a certain demographic (not necessarily economic - education level could be a factor) was exposed to that research and accepted it without questioning it, and therefore opted not to vaccinate.

As for the HPV vaccine, I believe there is some connection being made between 'needing' that vaccine and the perception of being sexually active.  This is the one also known as the 'Gardasil' vaccine?  Some religious groups were against that one because it 'encouraged promiscuity', so religious inclination might be a factor. 

Although it's an economic factor, it might be worth looking into whether or not public clinics (frequented by lower-income or uninsured people) offered the HPV vaccine.  With the average wait time at one of those, people might opt to get the vaccine if they are already there, but not bother to set up a second or third visit (that would take up the entire day).

[Serephino]

I was thinking the same thing about free clinics.  If you're below the poverty line it's easier to get treatment believe it or not.  In my state you can get Medicaid.  Lucky me is stuck between the poverty line and being able to afford insurance.  The studies about the link to autism also play a part I'm sure. 

There was a series of 3 I was supposed to get (can't remember what it was now) that I only got the first one because it caused me to have a seizure.  At least that's what the doctor thought caused it because I had it a few hours after, all tests were fine, and I haven't had one since.   

[DarklingAlice]

Although it's an economic factor, it might be worth looking into whether or not public clinics (frequented by lower-income or uninsured people) offered the HPV vaccine.  With the average wait time at one of those, people might opt to get the vaccine if they are already there, but not bother to set up a second or third visit (that would take up the entire day).

Thank you, Oniya ^_^ That's an excellent suggestion, and one I hadn't considered. I think I overlooked it because the free clinic I volunteer at (and all the other free clinics I know of in the area) can't treat minors. I do not know if that is a national thing though.

And yes, there is some inane hullabaloo regarding the HPV vaccine (because apparently teenage girls will be kept from sex if we leave them vulnerable to contracting cervical cancer forty years down the road), although I am not sure that the effects of that would play out across economic lines.

If I get a chance I will look into MMR vaccine confidence and its relation to race/ethnicity. Although that raises the question of why MMR confidence/anti-vac would be a racial/ethnic issue. To the best of my knowledge, education gaps correlate more readily with economic gaps rather than with racial factors so I doubt that is the culprit. It is possible though.

[Oniya]

I'm not thinking that MMR is a racial/ethnic disparity as much as a - for lack of a better word - gullibility disparity.  There are people that are reasonably well educated and of decent economic standing that will still believe the latest infomercial coming down the pike.

As far as the free clinic thing - are they not even allowed to treat minors who come in with parental consent?

[cassia]

I wonder if access to higher quality medical care in general, and paid sick days for adults, might not also be a factor. Someone who has access to good doctors without a long wait time might have less to fear from rare or mild illnesses. They probably won't get sick, and if they do, they can go to the doctor for treatment and suffer nothing but discomfort and some small co-payments. Prevention of uncommon illness with a vaccine, for a person without extreme immune system difficulties and with inexpensive access to a doctor any day of the week, is not as important.

[DarklingAlice]

I wonder if access to higher quality medical care in general, and paid sick days for adults, might not also be a factor. Someone who has access to good doctors without a long wait time might have less to fear from rare or mild illnesses. They probably won't get sick, and if they do, they can go to the doctor for treatment and suffer nothing but discomfort and some small co-payments. Prevention of uncommon illness with a vaccine, for a person without extreme immune system difficulties and with inexpensive access to a doctor any day of the week, is not as important.

This could very well be true, however I am not sure you are quite cognizant of the extent of HPV infection. HPV is the single most common sexually transmitted disease in the US, and the CDC estimates that 50% of sexually active people will contract the virus at some point in their life. Now, it is true that 90% of those infected will be asymptomatic (either due to immune response or due to having contracted a mild strain of the virus). The remaining 10% will suffer a range of symptoms including: genital warts, warts within the respiratory system, and cancer of the cervix, vulva, vagina, penis, anus, tongue, or tonsils (generally depending on the strain of virus contracted and infection site). Indeed HPV is almost the sole source of cervical, vaginal, and anal cancers. Not problems that one can be solved with a simple trip to a doctor and a co-pay.

However, your not knowing that brings up another interesting hypothesis. Perhaps something is skewing the levels of education re: STDs on either side of the poverty line. If there are free clinics or awareness programs that target the lower economic level (or, given the controversy Oniya mentioned, political or religious disinformation programs targeting the higher economic level), then those in the lower economic level just might have a better understanding of the risks and consequences involved.

As far as the free clinic thing - are they not even allowed to treat minors who come in with parental consent?

To the best of my knowledge we cannot. I am not actually sure of the reason. It might have something to do with liability, or it might be due to some certification issue. It could also have something to do with regulations involving our volunteer staff. For instance, we cannot dispense certain drugs because doing so would bar everyone save certified pharmacists and pharmacy technicians to work in our dispensary, rendering the majority of our volunteer workforce useless. So there may be similar tight regulations on treating minors. I know we already have an awkward time with HIPAA as it is (e.g. getting translators and dispensary staff access to patient charts they need to do their jobs). I'll ask on Tuesday.