The difference between in-hospital CPR and out-of-hospital CPR is that out-of-hospital CPR does not have immediately available resuscitation equipment and medications, and is usually performed purely by hands-only CPR (usually BLS), and the call for help is from the emergency center; whereas for in-hospital CPR, not only is there equipment and medications available (which can be ALS), but the call for help is from the hospital's medical team that handles the emergency. It should be said that the speed of response will be faster than out-of-hospital, and as a hospital such a specific place, the degree of mastery of the technology of unarmed CPR is also higher.
But as far as Hands-Only CPR is concerned, it's the same in or out of the hospital.