PHILADELPHIA, Nov. 14, 2016 /PRNewswire-USNewswire/ -- Children hospitalized for medical or surgical procedures who have an existing mental health condition stay in the hospital longer than children without these conditions. Pediatric researchers who analyzed a national database recommend that health care policymakers and hospital administrators improve systems to more efficiently provide mental health care to hospitalized children. The research, published online Nov. 11 in Pediatrics, is the first study to show how comorbid mental health conditions, such as anxiety, ADHD and depression, can impact a child's care in the hospital. "Most hospitalized children and their families are eager to go home as soon as they can - extra days in the hospital are missed days at school for kids, missed days at work for parents and a disruption to family routines," said lead author Stephanie Doupnik, MD, a researcher in PolicyLab at Children's Hospital of Philadelphia. "Unfortunately, we're seeing that mental health conditions add a layer of complexity to hospital care that causes kids with mental health conditions to stay in the hospital longer and use additional resources." Investigating 670,000 hospitalizations in the 2012 Kids' Inpatient Database, the study team found that existing mental health conditions were present in one in seven medical and surgical hospitalizations of children aged 3 to 20. For nine types of surgical procedures - including appendectomy, knee procedures and gall bladder removal - having one mental health condition increased 61 percent of children's hospital stays by one day. In this same population, having two or more mental health conditions added one day to every child's stay. For nine types of medical hospitalizations - such as chemotherapy, headache and diabetes - having one mental health condition added an extra day in the hospital for 28 percent of children. Furthermore, having two more mental health conditions added a day to 50 percent of these children's hospital stays.