Literature Search: Smoking exposure and kids

Texas will ban smoking in the homes of foster kids beginning January 1. For some reason, there are not many articles in the News on this subject. (There is this editorial from my hometown.)

I would guess there's not much media attention because the deadline is a month away and because the rationalization is supposed to be a slam dunk. I'm sure any objection won't be popular.

So, I did a Pub Med search or two, on "passive smoking ear infections," "otitis media," and some more I can't remember. Although I found quite a bit of assumptions and mention of increased risk, the data is not as conclusive as I expected, except for "wheezing." (I will have to admit that I wasn't surprised, since I remember some studies from the '80's and '90's that showed conflicting risks of cancer from second hand smoke at home in wives and in children of smokers.)

This article shows a correlation between carriage of Streptococcus pneumoniae in children whose mothers smoke, with a probability of P=0.016. I'm used to seeing numbers that show probability <0.01 or <0.05 - meaning that there's less 1% or 5% chance of being a coincidence.

Then there's this review in Pediatrics (free copy) that does show correlations, but no real data or tables.

On the other hand, I found some significant articles with no correlation or inconsistent correlation with childhood infections.

Free text and tables
"Respiratory Infections" from Norway study on over 3000 10 year olds.
Here's the table showing risk factors for ear infection, tonsilitis, and lower respiratory infections. (sorry, my skills aren't up to posting the table.)

This article shows no correlation with ear infection and passive smoke, although there is a correlation between being exposed before birth and after birth with recurrent ear infections:
Archives of Pediatrics, AMA (Free full text with free registration):

RESULTS: The cumulative incidence of ear infections was 69%. Of all participants, 38% were exposed to passive smoke, 23% were exposed to gestational smoke, and 19% were exposed to combined passive and gestational smoke. The occurrence of any ear infection was not increased by passive smoke exposure (adjusted risk ratio [RR], 1.01; 95% confidence interval [CI], 0.95-1.06), but was slightly increased by gestational (adjusted RR, 1.08; 95% CI, 1.01-1.14) and combined (adjusted RR, 1.07; 95% CI, 1.00-1.14) smoke exposures. The risk of recurrent ear infections (> or = 6 lifetime episodes) was significantly increased with combined smoke exposure (adjusted RR, 1.44; 95% CI, 1.11-1.81). Other risk factors for ear infection identified in multivariable analysis were race/ethnicity, poverty-income ratio of 2.00 or more, attendance in day care, history of asthma, and presence of allergic symptoms. CONCLUSIONS: Passive smoke exposure was not associated with an increased risk of ever developing an ear infection in this study. The increased risk found with gestational and combined smoke exposures has marginal clinical significance. For recurrent ear infections, however, combined smoke exposure had a clinically and statistically significant effect.

For those concerned about smoking risks for children, please consider reading this free article, which has been translated into English, from the Jornal de Pediatra, a fantastic review of the literature on risk factors ("RF") for recurrent and chronic ear infections.

In conclusion, although some authors declared the relation between RAOM and COME with passive smoking as established, others are totally against such affirmation. It may be said that passive smoking does not increase the chance of non-recurrent AOM (level of evidence IV). With regard to recurrent AOM and COME, passive smoking was classified as a probable RF (level of evidence II).