Table 1 Summary of existing work with PRECIS

Riddle (2010) Pain coping skills training for patients - knee arthroscopy

0-4 cm circle VAS

X

1

7

YES (individual scoring then consensus score)

Useful to focus trial design discussion. PRECIS scoring: Initial, personal ideal and then post meeting. 1-day face-to-face meeting to discuss trial. PRECIS facilitates discussion.

Trial design changed: domain ‘practitioner expertise’ - needed to do psychologist training and domain ‘practitioner adherence’ - rigorous ongoing assessment to check intervention as intended. Visual analogue scale cannot be used if ‘online ratings’.

Glasgow (2010) Weight loss in obese patients with comorbid conditions

0-4 scale

3

X

9

NO

PRECIS improved ‘transparency’ in trial design decisions, encouraged others to use.

Domain most variation: Primary analysis.

Trialists rate own trial more pragmatic than other raters. Not clear if original criteria are sufficient to provide a comprehensive profile.

Tosh (2011) Mental health

1-5

X

10

3

NO

‘Useful tool’. Cumulative scores for all 10 PRECIS domains. Experimental 0–15, Pragmatic >35, 31–19 interim where trial balances pragmatic and explanatory domains. Scoring depends on rater’s perspective. 0 for missing information

Koppenhaal (2011) Systematic review on lifestyle improvements in General Practice

1-5%

20

X

2

YES (individual scoring then consensus score)

‘Useful estimate by estimating quantitatively how pragmatic each RCT is’. Chose PRECIS as explanatory/pragmatic continuum and visual analogue scale. Domains most variation: Practitioner expertise (comparison), primary analysis. Tried 1–10 score but too much difference between consecutive scores not meaningful, still concerned arbitrary - important to reduce subjectivity so two raters (third rater if not consensus). Weighting could be important; eligibility criteria important but flexibility of the comparison intervention may be less important. Problems using PRECIS due to reporting as CONSORT guidelines not being followed.

Bratton (2011)

No scoring

3

X

2

Joint discussion

Blinding inserted and combined experience of practitioner expertise for comparison and experimental intervention as postulated no difference in expertise in these trials.

Bratton (2012)

1 (ongoing)

X

6

NO

‘Useful tool for designing, conducting and reporting trials’. Strongest consensus ‘flexibility of the comparison intervention’ and ‘practitioner adherence’ domains. Most disagreement on ‘eligibility criteria’ and ‘participant compliance’.

Witt (2012)

1-5

10

X

5

YES (individual scoring then consensus score)

“PRECIS useful but needs further development”. CONSORT guidelines for reporting pragmatic trials should be expanded. Recognised that PRECIS originally intended for trial design but useful tool for appraising published RCTs for systematic reviews.

Selby (2012)

1-20

X

1

6

YES (individual scoring then consensus score)

PRECIS useful to help interdisciplinary co-investigators rate their study design. Used two rounds of Modified Delphi process used to reach consensus. 20-point numerical scale approximated a continuous scale allowing ‘easier, more accurate and more stable coding of the response using e-mail’ - extreme anchor points 1–20, discouraged rating the domains beyond the numbers provided.