Table 1

Characteristics of patients with rare diseases in primary care, National Ambulatory Medical Care Survey 2012–2014 (unweighted n=22 306, weighted n=354 507 772)

Patients with rare diseases
Patients without rare diseases
P value
Unweighted sample size36321 943
Weighted sample size5 581 791348 925 981
Mean age (years)*47.739.4<0.001
 Non-Hispanic White75.070.60.54
 Non-Hispanic Black8.610.1
Insurance types
 Private insurance49.354.60.15
 Public insurance47.340.0
Major reasons for this visit*
 New problems33.742.60.002
 Chronic problems39.028.7
 Preventive care0.00.0
Total number of chronic diseases*
  • *Statistical significant level at 0.05.