Problem: Researchers were interested in studying perceptions and preferences for integrating mental health counseling with chronic disease in South Africa. They conducted in depth interviews for 30 patients receiving treatment for HIV or diabetes within primary care facilities who screened positive for depression or hazardous alcohol use. Participants considered it acceptable to offer screening and mental health counseling within the context chronic disease care. They thought counseling would be highly relevant if it helped patients develop adaptive strategies for coping with stress and negative emotions. What type of study design is this?