Respondents are asked to rate how bothered they have been by each of 20 items in the past month on a 5-point Likert scale ranging from 0-4 (0 = Not at all, 1 = A little bit, 2 = Moderately, 3 = Quite a bit, 4 = Extremely). Items are summed to provide a total severity score (range 0-80).
The PCL-5 can determine a provisional diagnosis in two ways:
- Summing all 20 items (range 0-80) and using a cut-point score of 31-33 which appears to be reasonable based upon current psychometric work. However, when choosing a cut-off score, it is essential to consider the goals of the assessment and the population being assessed. The lower the cut-off score, the more lenient the criteria for inclusion, increasing the possible number of false-positives. The higher the cut-off score, the more stringent the inclusion criteria and the more potential for false-negatives.
- Treating each item rated as 2 = ‘Moderately’ or higher as a symptom endorsed, then following the DSM-5 diagnostic rules which requires at least: 1 Criterion B item (questions 1-5), 1 Criterion C item (questions 6-7), 2 Criterion D items (questions 8-14), 2 Criterion E items (questions 15-20). In general, use of a cut-off score tends to produce more reliable results than the DSM-5 diagnostic rule.
If a patient meets a provisional diagnosis using either of the methods above, they need further assessment (e.g., Clinical Administered PTSD Scale for DSM-5: CAPS-5) to confirm a diagnosis of PTSD.
There are currently no empirically derived severity ranges for the PCL-5.