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Table 4 Primary and secondary outcomes in per-protocol and intention to treat population a

From: Restoring Study PRGF: a randomized clinical trial on plasma rich in growth factors for knee osteoarthritis

Primary outcome

PRGF

HA

Proportion mean difference (95% CI)

p value

n/N (%)

 % of patients with a decrease >50% in the score in the WOMAC pain subscale (non-preplanned)

PP analysis

34/78 (43.6%)

21/74 (28.4%)

15.2% (0.2 to 30.3)

0.051

ITT analysis

34/89 (38.2%)

21/87 (24.1%)

14.1% (0.5 to 27.6)

0.044

 % of patients with a decrease >40% in the score in the WOMAC pain subscale b

(preplanned)

PP analysis c

39/78 (50.0%)

33/74 (44.6%)

5.4% (−10.4 to 21.3)

0.505

ITT analysis

39/89 (43.8%)

33/87 (37.9%)

5.9% (−8.6 to 20.4)

0.427

Secondary outcomes

n/N (%)

Proportion mean difference (95% CI)

p value

 % of patients with a decrease >40% in the score in the VAS b

PP analysis c

36/79 (50.0%)

36/74 (44.6%)

−3.1% (−18.9 to 12.7)

0.206

ITT analysis

36/89 (40.4%)

36/87 (41.4%)

−0.9 (−15.5 to 13.6)

0.900

 % of patients with a decrease >40% in the score in the Lequesne index b

PP analysis c

53/77 (68.8%)

43/73 (58.9%)

9.9 (−5.4 to 25.2)

0.206

ITT analysis

53/89 (59.6%)

43/87 (49.4%)

10.1 (−4.5 to 24.8)

0.177

Secondary outcomes

Mean (95% CI)

Mean difference (95% CI)

p value

 Degrees of knee flexion

PP analysis c

126.6

(123.2–129.9)

124.8

(121.4–128.1)

1.8 (−2.9 to 6.5)

0.447

  Visit 1 (1 month)

 Degrees of knee flexion

128.1

(125.4–130.9)

128.4

(125.6–131.2)

−0.3 (−4.2 to 3.6)

0.883

  Visit 2 (2 months)

 Degrees of knee flexion

128.4

(125.6–131.1)

128.8

(126.0–131.6)

−0.5 (−4.4 to 3.4)

0.809

  Visit 3 (6 months)

 Use of acetaminophena,d (g/day)

ITT analysis

0.1 (2.0)

0.1 (2.3)

---

0.853

  1. CI confidence interval, g grams, HA hyaluronic acid, ITT intention-to-treat, PP per-protocol, PRGF plasma rich in growth factors, VAS Visual Analogue Scale, WOMAC Western Ontario and McMaster Universities Osteoarthritis Index
  2. aA per-protocol analysis [>50% in the WOMAC pain subscale] and three intention-to-treat (ITT) analyses [>40% in the WOMAC pain subscale; >40% in the VAS; and >40% in the Lequesne index] have been estimated and presented by our team to let readers know about potential differences in dichotomic primary and secondary outcomes when an alternative strategy of analysis is performed. This information can help to evaluate the discrepancy between the analysis strategy planned in the protocol (a per-protocol analysis) and the one followed in the original publication (an ITT analysis)
  3. bOutcome defined in the study protocol as >40% but results in the final report informed as ≥40%
  4. cNot adjusted results with standard errors for the continuous variables and number of events with p values for dichotomous outcomes are provided in the final report. Based on that, standard deviations and subsequent confidence intervals have been calculated and presented for a per-protocol analysis. An ITT analysis was also performed for the continuous variable (PRGF, n=89; hyaluronic acid, n=87), which results are not shown to avoid redundancy as they were essentially similar to the PP analysis
  5. Results for several pre-planned secondary outcomes [% patients with a function increase ≥30% in the score in Lequesne and WOMAC, quality of life, investigational / inflammatory markers and indicators of cartilage metabolic imbalance] are not available
  6. dUse of acetaminophen (g/day) expressed as median and range, only for the intention-to-treat analysis. Additional data from the final report were not considered for publication because of information incompleteness, which prevents us from providing reliable data
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ISSN: 1745-6215