PMC:4161609 / 24787-24972
Annnotations
{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/4161609","sourcedb":"PMC","sourceid":"4161609","source_url":"https://www.ncbi.nlm.nih.gov/pmc/4161609","text":"Please choose one answer from the five choices below that best describes the frequency of your symptoms over the past month: 0, never; 1, occasionally; 2, sometimes; 3, often; 4, always","tracks":[]}