Mood inventories like the PHQ-9 or Kessler are very useful in primary care as patients can appear OK but have very low moods. A single question, The Emoqol 1001, has been developed to enable clinicians to get a quick assessment of their patients' mood.
The question narrative goes like this: "How is your emotional quality of life now, with 100 being perfect and zero being worst imaginable?"
It has a sensitivity of 47% and specificity of 93%. What that means is if their score is 50 or less, the person is very likely to have a PHQ-9 score of ≥ 10, which indicates a low mood. It takes about 15 seconds to ask, is simple and does not require the patient to have their glasses handy.
As published in NZ Doctor
As published in Research Review