It seems Rugby-World-Cup-related sex is dangerous. I can't access the original article as the journal is currently returning a 503 error code, so I'll have to rely on the newspaper reporting.
According to the New Zealand Herald, folks attending Sexual Health Clinics around the time of the Cup were surveyed. Those reporting having had RWC-related sex, about 7% of the sample, had higher risk of STDs, often reported having consumed alcohol before the act [the DomPost says 70% had consumed alcohol], and rarely reported having used condoms. From this, the authors argue for reduced promotion and availability of alcohol around future large sporting events.
Again, I haven't access to the article. But a few things come to mind.
First, sample selection is an awfully large problem here. 151 people attended a Sexual Health Clinic after having had RWC-related sex. How many people had sex after a fun night out watching the matches, didn't wind up with suspicious itches or discharges, and so didn't go to visit a Sexual Health Clinic? What was the rate of alcohol or condom use among those who failed to show up at a Sexual Health Clinic? How many of them simply had a great time without negative consequences? Recall that alcohol consumption correlates with positive sexual experiences.
A second sample-selection issue is that folks reporting RWC-related sex are probably really reporting "sex after hooking up at a RWC party or event", which won't be that different from "sex after hooking up at any party or event". And, in that case, again, is the fault with the alcohol, or is it that people going out and wanting to have a good time are more likely to drink and also more likely to think that hooking up is fun? Recall that the answer to "Do you like beer?" is a significant predictor of whether someone will have sex on the first date. The omitted underlying variable is then likely some combination of sensation-seeking, risk preference, and hedonism. Unless you control for that underlying heterogeneity, you're going to draw some awfully misleading conclusions from straight correlations among the various outcomes of that underlying agent-type.
Finally, here's how the Herald describes "RWC-related sex":
People who had RWC-related sex were defined as New Zealanders who had sex related to the RWC or other associated events, New Zealanders whose sexual event leading to the clinic visit was with an overseas visitor primarily in New Zealand for the RWC, and individuals visiting New Zealand primarily for the RWC.So, basically then, people who report having hooked up with a tourist, tourists hooking up with locals, and folks hooking up at parties are more likely to engage in riskier sexual activities, many of them have had a few drinks, and some of them show up at Sexual Health Clinics. Policy conclusion: crack down on alcohol.
About 133,000 tourists showed up for the RWC; rather a few locals attended RWC events. 151 people showed up at Sexual Health Clinics afterwards. Suppose that ten percent of the tourists here for the RWC had some kind of RWC-related sex with locals, each only having one local partner. That's then about 26,500 people having had RWC-related sex; add to that locals hooking up with each other. I have no clue how close to right those estimates are. But I'd be pretty surprised if that 151 were more than 1% of the total RWC-related hook-ups. And this is the basis for an alcohol crackdown?
Otago remains an interesting place.