Creatinine levels relate to both muscle mass and to kidney function. As you age, your muscle mass decreases but your kidneys tend to function less effectively. The net result is not much change in creatinine levels in the blood as you get older.
As a result, California employers are required by law to have workers' compensation insurance, even if they have only one employee. And, if your employees get hurt or sick because of work, you are required to pay for workers' compensation benefits.
If the employee or the employer decides to make a workers' compensation absence a family and medical leave, then the employer cannot charge the employee for paid sick leave or any other form of employee compensation for time off. If the employer designates the workers' compensation time as FMLA, he must notify the employee in writing.