Editor's note: Inc.com columnist Alison Green answers questions about workplace and management issues--everything from how to deal with a micromanaging boss to how to talk to someone on your team about body odor.

A reader writes:

What is the appropriate way to talk to an employee who tends to take Thursday afternoons and Fridays and Mondays as sick time? I would think some of these are legitimate, but the pattern is somewhat obvious and my boss has even noticed and is wondering if this employee is really just taking vacation time.

First, make sure it's truly a pattern and not just something that happened, say, twice. But assuming it is...

"Jane, I'm concerned about your sick leave use. I've noticed that your sick time has tended to frequently fall just before or just after a weekend."

Then, wait and see what your employee says. That's important because there could be a legitimate reason for the pattern that you'd want to know about before plunging ahead. For instance, if it turns out that your employee has a standing medical treatment on Thursdays that causes nausea for the next several days, that will change the conversation, probably to one where you talk about better ways to plan for it.

But assuming nothing like that surfaces, you can proceed to: "Sick leave is different from vacation leave because it's unplanned. That means it has more of a disruption on our work. I don't want to discourage you from using it when you truly need it, but I'm concerned about the pattern I'm seeing, because I need you to be reliably here and because it's likely to cause resentment in coworkers over time. I'd like us both to keep an eye on this going forward."

That's it. By raising the issue, you're alerting the employee to the fact that you're on to the pattern, which makes it a lot less likely that it'll continue in the future. (Although if it does, you can address it at that point, referring back to this conversation.)

You also want to ground your thinking about this issue in what you know of the employee aside from this. Is she generally diligent and conscientious, with a high work ethic? Or does she have a lax attitude more broadly? How's her work overall? If she's generally a good employee, your tone in this conversation might simply be concerned -- a tone that says "I feel I need to point out this pattern, but it seems out of character for you and I wouldn't be surprised to learn there's a reason for it." But if she's not (and I'm betting she's not, because this type of thing generally shows up in employees who aren't top performers), then take this as a flag to address the overall performance issues with her as well -- because you need to, and because doing that will be more straightforward than second-guessing what she really did the last three Fridays she was out anyway.

By the way, some people would tell you to require doctor's notes from this employee going forward. That's certainly an possibility, but in general doctor's notes are a poor option. Requiring a doctor's note discourages people from staying home when they're sick, is an unfair burden (who wants to drag themselves to a doctor when a few days of resting in bed will cure them?), drives up health care costs by pushing people to the doctor when they only need home care, and signals to your employees that you don't trust them. It's better to simply trust your staff to behave responsibly and address it head-on if they don't.

Want to submit a question of your own? Send it to alison@askamanager.org.