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. 2018 Apr 24;2018(4):CD008201. doi: 10.1002/14651858.CD008201.pub3

Piazza 2009.

Methods

  • RCT

  • Non‐cluster

  • Unit of randomization: participant

  • Unit of analysis: participant

  • Study period: 2006 to 2007
Participants

  • USA

  • 25 centers

  • Departments: medical and surgical services excluding neurology, newborn, neonatal ICU, and rehabilitation units

  • Medical and surgical patients

  • Inclusion criteria: at least 18 years old, medical or surgical services, high risk of VTE, not receiving any VTE prophylaxis

  • Exclusion criteria: patients on neurology services, newborn service, neonatal ICU, rehabilitation units, patients not at high risk of developing VTE

  • N included: 1255 (control), 1238 (intervention)

  • Age (range, mean (SD)): control = 19 to 103, 68.28 (14.99), intervention = 20 to 100, 69.3 (15.46)

  • Male %: 53.4 (control), 54.5 (intervention)

  • Control group: concurrent with intervention group, observed over the same time as intervention group; same types of participants (department/hospital) as intervention group
Interventions

  • Aimed at doctors

  • Use of reminders: human alert

  • Responsible physicians alerted by another staff member if his or her patient was at high risk for VTE, and that VTE prophylaxis was recommended, based on point scale of DVT risk factors

  • Comparator: doctors were either alerted or not alerted
Outcomes

  • Appropriateness of prophylaxis not assessed

  • Received prophylaxis: 20.6% (control), 46% (intervention)

  • Symptomatic VTE (within 90 days): 3.4% (control), 2.7% (intervention)

  • Symptomatic DVT (within 90 days): 2% (control), 1.6% (intervention)

  • Symptomatic proximal DVT (within 90 days): 1% (control), 0.3% (intervention)

  • Symptomatic PE (within 90 days): 0.7% (control), 0.4% (intervention)

  • Symptomatic DVT + PE (within 90 days): 0.6% (control), 0.6% (intervention)

  • Major bleeding (within 30 days): 2.3% (control), 2.1% (intervention)

  • All‐cause mortality (within 90 days): 16.9% (control), 17.6% (intervention)

  • Method of VTE diagnosis: Doppler ultrasound, venography, ventilation‐perfusion scan
Notes Funding sources: Quote: "This investigator‐initiated study was funded in part by an unrestricted research grant from Sanofi‐Aventis, and Dr Piazza is supported by a Research Career Development Award (K12 HL083786) from the National Heart, Lung, and Blood Institute (NHLBI)."
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Unclear risk Quote: "Randomization envelopes containing the statement 'alert' (intervention group) or 'no alert' (control group) were provided by the Harvard Clinical Research Institute to randomize eligible patients." (Page 2197, column 2, paragraph 4)
Allocation concealment (selection bias) Unclear risk No information on whether the envelopes were sealed or opaque, etc.
Blinding of participants and personnel (performance bias) 
 All outcomes Unclear risk Quote: "All end points were adjudicated by investigators who were unaware of the patients’ group assignments." (Page 2198, column 1, paragraph 2)
There was no mention of the blinding of all participants and personnel.
Blinding of outcome assessment (detection bias) 
 All outcomes Low risk Quote: "All endpoints were adjudicated by investigators who were unaware of the patients’ group assignments." (Page 2198, column 1, paragraph 2)
Incomplete outcome data (attrition bias) 
 All outcomes Low risk Quote: "Overall, 2493 (100%) had follow‐up data beyond the index hospitalization." (Page 2197, column 2, paragraph 6)
Selective reporting (reporting bias) Low risk All relevant outcomes (clinical and safety outcomes) were assessed. (Page 2198, Table 1‐2; page 2199, Table 3)
Other bias Unclear risk Quote: "Because most physicians treated both intervention and control patients, it is possible that receiving a physician alert for patients in the intervention group also affected the use of prophylaxis in the control group." (Page 2200, column 2, paragraph 2). There was a possible dependence between physicians in the intervention and the control group.
Quote: "The intervention and control groups were similar with regard to baseline characteristics, except that patients randomized to a physician alert were more likely to be > 75 years (42.5% versus 37.8%; P=0.02; Table 1)." (Page 2198, column 2, paragraph 2)
Quote: "One study center that enrolled 178 patients violated the study protocol and paged house officers rather than the attending physicians." (Page 2197, column 2, paragraph 4)
Low risk of bias for other items listed as potential sources of bias