Table 3. Twenty Most Frequently Recorded ICD-9 Diagnosis Codes for Trial Participants*
Diagnosis CategoryParticipants, n (%)
Hypertension, not otherwise specified397 (47)
Tobacco use disorder388 (46)
Depressive disorder, not elsewhere classified361 (43)
Pain in limb296 (35)
Chronic pain, not elsewhere classified256 (30)
Lumbago244 (29)
Cough217 (26)
Hyperlipidemia, not elsewhere classified/not otherwise specified207 (24)
Vaccine for influenza201 (24)
Physical therapy, not elsewhere classified195 (23)
Abdominal pain (unspecified site)193 (23)
Chest pain, not otherwise specified192 (23)
Viral hepatitis C (unspecified without mention of hepatic coma)187 (22)
Lack of housing184 (22)
Diabetes mellitus (without mention of complication, type 2 or unspecified, not stated as controlled)180 (21)
Esophageal reflux179 (21)
Backache, not otherwise specified175 (21)
Anxiety state, not otherwise specified151 (18)
Palpitations146 (17)
Acute upper respiratory infection, not otherwise specified141 (17)
  • * Diagnosis categories are based on 2927 distinct International Classification of Diseases, Ninth Revision, codes, based on data collected for 848 participants in the 2 years before study enrollment.