Ioannidis is correct in asserting that many trials, particularly surgical ones, represent “wasted effort” due to unimportant clinically outcomes and also that trials should be optimally designed and properly randomised.
Randomisation and blinding in surgical trials is possible and can be extremely powerful. For example, Moseley et al used a double blinded placebo controlled study design to show there was no difference in pain or function in those who experienced knee arthroscopy compared to placebo surgery, despite arthroscopy being commonly used to treat knee pain at the time (1). This study prompted the Department of Veterans Affairs to immediately recommend that knee arthroscopy should not be performed for knee pain in the absence of anatomic or mechanical abnormalities (2).
In another example, although minimally invasive hip replacement surgery had been widely reported as being beneficial in numerous cohort studies we successfully showed that, in a double blinded randomised controlled study, there was no improvement in early post operative outcomes (3), walking ability (4) or ability to mobilize (5), which were the main claims for this new technique.
Perhaps a good starting point would be to examine existing surgical procedures which lack adequate evidence of effectiveness rather than focus on studies of novel devices which currently seem to dominate the literature.
Yours
Dr Damien Bennett
Specialty Registrar in Public Health Medicine
(1) Moseley JB, O'Malley K, Petersen NJ, Menke TJ, Brody BA, Kuykendall DH, et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med 2002 Jul 11;347(2):81-88.
(3) Ogonda L, Wilson R, Archbold P, Lawlor M, Humphreys P, O'Brien S, et al. A minimal-incision technique in total hip arthroplasty does not improve early postoperative outcomes. A prospective, randomized, controlled trial. J Bone Joint Surg Am 2005 Apr;87(4):701-710.
(4) Bennett D, Ogonda L, Elliott D, Humphreys L, Lawlor M, Beverland D. Comparison of immediate postoperative walking ability in patients receiving minimally invasive and standard-incision hip arthroplasty a prospective blinded study. J Arthroplasty 2007 Jun;22(4):490-495.
(5) Lawlor M, Humphreys P, Morrow E, Ogonda L, Bennett D, Elliott D, et al. Comparison of early postoperative functional levels following total hip replacement using minimally invasive versus standard incisions. A prospective randomized blinded trial. Clin Rehabil 2005 Aug;19(5):465-474.
Rapid Response:
Ioannidis is correct in asserting that many trials, particularly surgical ones, represent “wasted effort” due to unimportant clinically outcomes and also that trials should be optimally designed and properly randomised.
Randomisation and blinding in surgical trials is possible and can be extremely powerful. For example, Moseley et al used a double blinded placebo controlled study design to show there was no difference in pain or function in those who experienced knee arthroscopy compared to placebo surgery, despite arthroscopy being commonly used to treat knee pain at the time (1). This study prompted the Department of Veterans Affairs to immediately recommend that knee arthroscopy should not be performed for knee pain in the absence of anatomic or mechanical abnormalities (2).
In another example, although minimally invasive hip replacement surgery had been widely reported as being beneficial in numerous cohort studies we successfully showed that, in a double blinded randomised controlled study, there was no improvement in early post operative outcomes (3), walking ability (4) or ability to mobilize (5), which were the main claims for this new technique.
Perhaps a good starting point would be to examine existing surgical procedures which lack adequate evidence of effectiveness rather than focus on studies of novel devices which currently seem to dominate the literature.
Yours
Dr Damien Bennett
Specialty Registrar in Public Health Medicine
(1) Moseley JB, O'Malley K, Petersen NJ, Menke TJ, Brody BA, Kuykendall DH, et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med 2002 Jul 11;347(2):81-88.
(2) Gordis L. Epidemiology. 4th ed. Philadelphia, Pa. ; London: Saunders; 2009.
(3) Ogonda L, Wilson R, Archbold P, Lawlor M, Humphreys P, O'Brien S, et al. A minimal-incision technique in total hip arthroplasty does not improve early postoperative outcomes. A prospective, randomized, controlled trial. J Bone Joint Surg Am 2005 Apr;87(4):701-710.
(4) Bennett D, Ogonda L, Elliott D, Humphreys L, Lawlor M, Beverland D. Comparison of immediate postoperative walking ability in patients receiving minimally invasive and standard-incision hip arthroplasty a prospective blinded study. J Arthroplasty 2007 Jun;22(4):490-495.
(5) Lawlor M, Humphreys P, Morrow E, Ogonda L, Bennett D, Elliott D, et al. Comparison of early postoperative functional levels following total hip replacement using minimally invasive versus standard incisions. A prospective randomized blinded trial. Clin Rehabil 2005 Aug;19(5):465-474.
Competing interests: No competing interests