If your home isn't newly built, you'll probably be able to replace the existing knob hardware on your mortised lock sets with levers. Most residential construction uses cylindrical lock sets and latches which are difficult to replace with levers. But several devices have been introduced recently for adding a lever arm to existing cylindrical latch sets. For information about these products, refer to the Resources chapter. The security you desire for your home may be difficult to achieve if you have hand dexterity impairments.
Most locks require fine dexterity and finger strength.
Using the closed fist rule, you can easily determine whether your locks are useable by older persons in your household who have arthritis. Lever hardware is preferable to any kind of small twist knob. Push buttons may be satisfactory if they don't require fine dexterity to release the lock. A push button lock in a cylindrical lever latch is perfect from an operational point of view, but it doesn't generally provide the security of a dead bolt mechanism. Slide bolts, however, are fairly easy for anyone to operate and provide nearly the same security as dead bolts.