Table 1

Detailed healthcare utilisation and total costs of treatment with rifampin for 4 months (4RIF) vs isoniazid for 9 months (9INH) (all costs in Canadian $)

4RIF9INHp Value*
Total costTotal per patient allocatedTotal per patient completedTotal costTotal per patient allocatedTotal per patient completed
Scheduled care
 Clinical visits
  MD±RN follow-up$94177$152842
  RN follow-up$39611$73005
  Subtotal clinical visits$202122$481$616$295320$692$1158
  Pharmacy fees$10373$20251
  Drugs for LTBI$94825$25609
  Subtotal treatment of LTBI$105198$250$321$45860$107$180
  Complete blood count (CBC)$11628$11277
  Liver transaminases$14057$13681
  Subtotal investigations$25684$61$78$24958$58$98
 Subtotal: scheduled care$333005$792$1015$366138$857$14360.026
Non-scheduled care
 Clinical visits
  Emergency room visit$179$894
  Unscheduled clinic visit$701$1051
  Specialist consultation$2937$3247
  Visit to evaluate adverse events$9415$18691
  Telephone call$46$162
  Visit to perform blood tests$725$1670
  Subtotal clinical visits$14003$33$43$25715$60$101
Subtotal treatment for side effects$218$1$1$226$1$1
 Additional CBC$3635$7726
 Additional liver transaminases$4766$10966
 Other investigations
  Blood chemistries$844$910
  Hepatitis serology$256$425
  Iron or coagulation profile$233$337
  Other blood tests$280$440
  Pulmonary function tests$352$440
  Subtotal investigations$11464$27$35$22201$52$87
 Subtotal: non-scheduled care$25685$61$79$48142$113$1890.008
Overall total costs$3586908541094$414280$970$1625<0.0001
  • * Student t test comparing differences in costs per patient allocated to 4RIF vs 9INH. Differences in cost per patient completed greater, hence more significant. Total and subtotal costs normally distributed. Only three differences were tested.

  • 9INH, isoniazid treatment for 9 months; LTBI, latent tuberculosis infection. 4RIF, rifampin treatment for 4 months