Most of the chart review projects can be done in a week in terms of workload. The tricky thing is:
1. Make sure you are the first author. Last thing you want is you bust your ass off for a third author position. Fact is you can just socialize if you just want to get your name on a paper. I was once offered an authorship if I just proofread her manuscript just because we were gossip buddies. And that was a basic research paper.
2. Will your supervisor keep pushing the paper out? Just because you are a hard-worker doesn't mean your supervisor is.
3. Go to Chinatown and buy a budda charm so your work will not be scooped.
My second chart review paper was accepted in a IF=3 journal without revision 2 months after we submitted it. On the other hand, my first chart review paper, with 2x amount of work, was scooped, held off for half a year, some politics happened, got restarted, then took more than a year to get accepted in a IF=1 journal after two rejections.
So in summary, clinical projects are easier to get a paper out than basic research projects out but you still need luck.