RCT Critical appraisal

高雄長庚醫院外科加護護理長 長庚科技大學護理系講師

Cochrane Bone, Joint, Muscle Trauma Group

Basic information about the trial First author Olson DMOlson DM

Publication year 20092009

TitleEffect of mechanical chest Effect of mechanical chest percussion on intracranial percussion on intracranial pressure: a pilot studypressure: a pilot study

Country USUS

Funding source

National Institute for Nursing National Institute for Nursing Research (T32 NR07091 Research (T32 NR07091 Interventions to Prevent and Interventions to Prevent and Manage Chronic Illness)Manage Chronic Illness)

Levels of evidence pyramid(for therapy/prevention, aetiology/harm)

Ib

Are the results of the trial valid?Item 1Item 1 AppraisaAppraisa

l l CommentComments s

Was the assignment of Was the assignment of patients to patients to interventions interventions randomised?randomised?

■ ■ YesYes□ UnclearUnclear□ NoNo

所有患者依所有患者依隨機分為兩隨機分為兩組組

If the trial is not a RCT, we should put it aside unless there are no RCTs.

If the trial is not a RCT, we should put it aside unless there are no RCTs.

Are the results of the trial valid?Item 2Item 2 AppraisApprais

al al Comments Comments

Was the allocation Was the allocation concealed?concealed?

□YesYes■■UncleaUnclearr□NoNo

No descriptionNo description

Are the results of the trial valid?Item 3Item 3 Appraisal Appraisal Comments Comments

Were the groups Were the groups similar at the similar at the start of the trial?start of the trial?

■ ■ YesYes□ UnclearUnclear□ NoNo

在 在 mean age, gender, race, mean age, gender, race, post injury day, diagnosis post injury day, diagnosis 等等方面，兩組無明顯差異方面，兩組無明顯差異

Are the results of the trial valid?Item 4Item 4 AppraisApprais

al al Comments Comments

Was follow-up of Was follow-up of patients sufficiently patients sufficiently long and complete?long and complete?

■■YesYes□UnclearUnclear□NoNo

11:50 AM to 11:50 AM to 12:20 PM12:20 PM

Assuming the effect of chest percussion on ICP is instant and only transient

Assuming the effect of chest percussion on ICP is instant and only transient

Are the results of the trial valid?Item 5Item 5 AppraisApprais

al al CommeComments nts

Were all patients analysed in Were all patients analysed in the groups to which they were the groups to which they were randomised? (Intention-to-randomised? (Intention-to-treat analysis)treat analysis)

■ ■ YesYes□ UnclearUnclear□ NoNo

Are the results of the trial valid?Item 6Item 6 AppraisApprais

al al CommenComments ts

Were measures objective or Were measures objective or were the patients and were the patients and clinicians kept “blind” to clinicians kept “blind” to which intervention was being which intervention was being received?received?

■■YesYes□UnclearUnclear□NoNo

ICP ICP monitor monitor was was used.used.

Are the results of the trial valid?Item 7Item 7 AppraisApprais

al al CommenComments ts

Were groups treated Were groups treated equally, apart from equally, apart from the experimental the experimental therapy?therapy?

■ ■ YesYes□ UnclearUnclear□ NoNo

Are the results of the trial valid?Yes

Randomisation

Allocation concealment

Comparability of the groups

Follow up

Intention-to-treat analysis

Blinding/objective measures

Equal care

Yes (low risk of bias)

Unclear

No (high risk of bias)

If the results of the trial are valid, how important are they?

Item 1Item 1 Results Results CommeComments nts

What is the What is the magnitude of the magnitude of the intervention effect?intervention effect?

Results• Hypothesis testing was done by using 2-way

analysis of variance for median and mean values to explore within- and between-subject models.

• Mean and medial values were determined for the 10-minute epoch before chest percussion was performed on the intervention group (11:50 AM-noon), during chest percussion (noon-12:10 PM), and after chest percussion was performed on the intervention group (12:10-12:20 PM).

Between-patient model: no differences in ICP between the patients or

among the 3 time epochs• The between-patients models were insufficient to reject the

null hypothesis for the omnibus test of difference in mean ICP (F = 0.19, P = 0.83) or median ICP (F = 0.14, P = 0.87).

• Similarly, the data were insufficient to reject the null hypothesis of a difference in mean or median for any of the 3 time epochs (Table 2).

With-subject model: no differences among the 3 time epochs• The within-subject differences in

mean ICP across the 3 time epochs also were not significant (P = 0.96).

• The data (Table 3) were explored for comparison of slopes by using the general linear model. No evidence of unequal slopes was apparent across all 3 time periods combined (F = 0.55, P = 0.46) or for the 10 minutes during which the intervention group received chest percussion (F=0.10, P = 0.76).

If the results of the trial are valid, how important are they?

Item 1Item 1 Results Results CommentComments s

What is the What is the magnitude of magnitude of the the intervention intervention effect?effect?

•No differences in ICP No differences in ICP between the patients between the patients or among the 3 time or among the 3 time epochs.epochs.

•No differences in ICP No differences in ICP before, during, and before, during, and after chest after chest percussion.percussion.

Complicated Complicated multiple multiple comparisons comparisons did not show did not show differences differences in ICP after in ICP after chest chest percussion.percussion.

If the results of the trial are valid, how important are they?

Item 2Item 2 Results Results CommentComments s

How precise is the How precise is the estimate of the estimate of the intervention intervention effect?effect?

Low Low precisionprecision

13 vs. 15 13 vs. 15 participanparticipantsts

Are the results of the trial clinically relevant?

Yes

Can we apply the results of the trial to our patients?

Item 1Item 1 AppraisaAppraisal l

Comments Comments

Is our patient so Is our patient so different from those different from those in the trial that its in the trial that its results cannot apply?results cannot apply?

□ YesYes■ ■ NoNo□ UnclearUnclear

我們有同樣的我們有同樣的病人與情境病人與情境

Can we apply the results of the trial to our patients?

Item 2Item 2 Appraisal Appraisal Comments Comments

Is the intervention Is the intervention feasible in our feasible in our setting?setting?

■ ■ YesYes□ NoNo□ UnclearUnclear

我們有相同的我們有相同的設備與介入措設備與介入措施施

Can we apply the results of the trial to our patients?

Item 3Item 3 Appraisal Appraisal

What are our What are our patient’s patient’s potential benefits potential benefits and harms from and harms from the therapy?the therapy?

Benefits: Benefits: potential benefits potential benefits in preventing aspiration in preventing aspiration pneumonia.pneumonia.

Harms: Harms: No significant No significant potential harms.potential harms.

Can we apply the results of the trial to our patients?

Item 4Item 4 Appraisal Appraisal

(Optional) What are our (Optional) What are our patient’s values and patient’s values and expectations for both the expectations for both the outcome we are trying to outcome we are trying to prevent and the prevent and the intervention we are intervention we are offering?offering?

(( 手邊的病人手邊的病人 ))Patient’s values:Patient’s values:頭部外傷病人需預防肺頭部外傷病人需預防肺炎與感染合併症縮短住炎與感染合併症縮短住院天數。院天數。

Patient’s Patient’s expectation:expectation:希望有療效，且不傷身。希望有療效，且不傷身。

Can we apply the results of the trial to our patients?

Yes

感謝聆聽，敬請指教