Skip to main content

Table 5 Complete cost collection vs. incomplete cost collection and interpolation (by the respective quarters), n=234

From: Empirical analysis shows reduced cost data collection may be an efficient method in economic clinical trials

  Complete cost collection Incomplete cost collection
   Interpolation
   Omitted quarters
  Alt 0a Alt 4b Alt 5c Alt 6d
    Quarter 2 (by 1 and 3) Quarter 3 (by 2 and 4) Quarters 2 and 3 (by 1 and 4)
Cost category means (SD) means (SD) means in difference (StdErr) means (SD) means in difference (StdErr) means (SD) means in difference (StdErr)
Direct healthcare costs       
 Physicians 523.38 (358.27) 508.40 (343.27) 14.97 (8.58) 527.56 (383.66) 4.19 (7.03) 501.87 (344.89) 21.51 (11.62)
 Physiotherapist 69.29 (162.63) 64.97 (164.25) 4.31 (3.23) 71.61 (175.50) 2.32 (2.83) 65.37 (185.64) 3.92 (5.42)
 Ambulatory clinic in hospital 35.79 (110.83) 37.93 (142.50) 2.14 (3.66) 28.62 (84.32) 7.18 (5.45) 25.88 (76.71) *9.91 (5.88)
 Drugs 1315.52 (707.38) 1306.92 (701.52) 8.60 (7.23) 1304.79 (707.09) *10.72 (5.75) 1276.92 (692.75) **38.60 (12.53)
Sum of direct healthcare costs 1943.99 (936.67) 1918.23 (917.58) **25.77 (11.82) 1932.58 (962.72) 11.41 (10.89) 1870.04 (936.79) **73.95 (19.96)
Direct non-healthcare costs       
 Outpatient nursing service 145.44 (593.85) 138.62 (546.78) 6.82 (11.98) 142.76 (608.39) 2.67 (7.35) 126.47 (537.84) 18.97 (20.85)
 Paid household help 418.46 (2455.42) 410.15 (2442.17) 8.30 (21.42) 415.96 (2494.90) 2.50 (17.83) 396.86 (2506.58) 21.60 (39.02)
Sum of direct non-healthcare costs 563.89 (2568.91) 548.77 (2534.93) 15.12 (23.25) 558.73 (2611.32) 5.17 (19.07) 523.33 (2577.07) 40.57 (39.89)
Sum of costs 2507.88 (2864.38) 2467.00 (2807.64) 40.89 (28.29) 2491.31 (2911.74) 16.58 (21.78) 2393.36 (2836.42) **114.5 (47.70)
  1. *p-value of paired t-test/bootstrapping of differences between complete and incomplete cost collection <0.10.
  2. **p-value of paired t-test/bootstrapping of differences between complete and incomplete cost collection <0.05.
  3. aAlternative 0, complete cost collection.
  4. bAlternative 4, incomplete cost collection, omitted quarter 2, replaced by quarters 1 and 3.
  5. cAlternative 5, incomplete cost collection, omitted quarter 3, replaced by quarters 2 and 4.
  6. dAlternative 6, incomplete cost collection, omitted quarters 2 and 3, replaced by quarters 1 and 4.