I don't what to think about that, because due to severe sinusitis I kind of lost my smell sense when I was a teenager (I'm almost 30 now), yet I can smell pretty strong odours (mostly alcohol smell sensation and peppermint). It can't be really true that it's "5 years and you're dead" :D
The predictive power of the diagnosis, according to the article, depends on the loss of the smell being caused by the body's failure to regenerate the tip of the olfactory nerve through new stem cells. In your case, the cause is entirely different, and so your loss of smell doesn't have the same meaning. For example, if someone had his olfactory nerve surgically removed, it obviously would not mean he was likely to die within five years.
> 3,005 community-dwelling adults aged 57–85 were studied in 2005–6 (Wave 1) and their mortality determined in 2010–11 (Wave 2). Olfactory dysfunction, determined objectively at Wave 1, was used to estimate the odds of 5-year, all cause mortality via logistic regression, controlling for demographics and health factors.