We do on call at the 200 bed hospital that I work at, too. Luckily, we only have to float to one unit, other than our own. If hiring more staff (which has helped us cut down on call here lately) isn't an option, then you may be out of luck, because numbers in staff will make the biggest change. Not that money solves everything, but maybe offering more of an overtime incentive (for instance, at my last hospital, we got time and a half plus $10/hr for every hour we worked, plus $25 Chilis/Macaroni Grill gift cards
if you signed up at least one week in advance) will encourage people to sign up for scheduled overtime, therefore, cutting down on the number of call shifts you have to take. Although, if your hospital is like my current one, I guess extra money incentives aren't an option. Something else that might take some work, but could be effective is have people who call out on weekends take the place of someone else's call shift. Currently, our policy is that if you call out on a Fri, Sat, or Sun, then you will be placed on the next weekend shift that is short. The only way to have this waived is family death or personal illness requiring a trip to the doctor, which has to be documented and shown the the Nurse Manager. It seemed pretty harsh at first, but it has cut down drastically on call outs and so getting called in because someone else called out has become less of an issue. And people who really need to call out because their children are sick and cannot stay with husband, grandma, etc. have done a better job about calling around to see if someone will fill in for them so that they don't get penalized for calling out. I'm not sure what your absenteeism situation is and which days are the worst or if that is even part of the solution for you, but it's a thought. The other thing is like one person said, hire a float pool team. Again, not sure what your hospital's financial situation is. I'm guessing a for-profit who probably nickles and dimes everything, so a float pool may even be more costly? Hope this helps!