Are review articles the result of original observations? I am about to submit a PhD thesis by published work. The university guidelines states that "the content of the papers should be the result of original observations". I would like to include a review article I wrote last year. 

This review article does not report novel experimental data, but as a regular review article, it reports "observations" of the current state of research. 

Is this view correct? Can I include it in my thesis?
I think that review articles can of course be original work, provided that they offer something like an analysis of the current literature. A mere list of positions and the people who take them isn't going to count as a contribution to the literature. However, showing people that certain pieces of literature form families that have resemblences to one another, or that a certain piece has been cited a lot, although people have overlooked another important, but unknown piece that calls its thesis into question, etc. . .  those are all important, and indeed original contributions. 

I'm guessing that your article probably is analytical in this way, otherwise it wouldn't have been accepted for publication in the first place. I'd say that if it is a high-quality article, published somewhere respectable, then go on and include it in the thesis. Although obviously the usual caveats ("Check with your advisor!") apply.