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Table 3 Regression analysis of individual quality criteria versus year-of-publication of the manuscripts identified by the PubMed MEDLINE search This table lists the results of the regression analyses comparing year-of-publication against the individual quality criteria.

From: Effects of the search technique on the measurement of the change in quality of randomized controlled trials over time in the field of brain injury

quality criterion regression result
(W = Wald stat)
Cox & Snell R2 regression line
the assessment of the distribution of patient characteristics and prognostic factors between groups W = 0.96, P = 0.33 0.01 y = -0.075x + 9.45
prevention of the movement of patients between groups after allocation, and the use of intention-to-treat analysis W = 1.63, P = 0.20 0.02 y = 0.088x - 10.30
the blinding of the patients to the treatment they received W = 0.30, P = 0.58 0.003 y = 0.022x - 0.80
the blinding of the health care providers to the treatments received by the patients W = 2.00, P = 0.16 0.02 y = 0.055x - 5.71
the blinding of the outcome observer to the treatment received by the patient W = 0.01, P = 0.93 0.000 y = 0.003x + 0.57
adequacy of follow-up W = 0.03, P = 0.86 0.000 y = -0.006x + 1.18
allocation concealment W = 1.06, P = 0.30 0.011 y = 0.39x - 78.4