Table 1

Summary of impact analysis studies of CPRs relevant to primary care

Author, year, country	CPR name, CPR predictive accuracy (95% CI), study design	Population and study setting	Intervention and comparison	Primary outcome(s)	Results: primary outcome (95% CI)
Auleley, 1997, France15	Ottawa ankle rule sensitivity 100% (95% to 100%), specificity 50% (46% to 55%) cluster RCT	4980, ≥18 years, emergency departments of 5 Paris university teaching hospitals	Intervention: educational intervention to encourage CPR use (ie, posters, pocket cards and data forms). Postintervention: only posters used to sustain the intervention effect. Comparison: Usual care	Physician behaviour: Referral for radiography (ankle/foot)	Relative reduction intervention site: 22.4% (95% CI 19.8% to 24.9%), control group increase of 0.5% (95% CI 0% to 1.4%).
Cameron, 1999, Canada19	Ottawa ankle rule sensitivity 100% (95% to 100), specificity 50% (46% to 55%) controlled before–after	1648, ≥18 years, male 885, female 763 mean age 38 (18–91), emergency departments in 10 hospitals	Group A: little or no prior use of the CPR and educational intervention (educational meeting, posters, pocket cards and patient information leaflets). Group B: some prior use of the CPR and educational intervention. Group C: active local implementation of the CPR and no educational intervention.	Physician behaviour: Referral for ankle X-ray	No reduction referral for ankle X-rays: intervention before 73%, after 78%, p=0.11, control: before 75%, after 65%, p=0.022
Stiell, 1994, Canada, ER16	Ottawa ankle rule controlled before–after sensitivity 100% (95% to 100), specificity 50% (46% to 55%)	2342, ≥18 years, emergency departments of 2 hospitals	Intervention: educational intervention to encourage CPR use (ie, lecture, pocket cards, and posters). Postintervention: posters remained in ER. Comparison: Usual care	Physician behaviour: referral for radiography (ankle/foot)	Ankle X-ray: relative reduction 28% in intervention group, increase of 2% in control group (p<0.001). Foot X-ray: relative reduction of 14% intervention group, increase of 13% in control group (p<0.05).
Boutis, 2013, Canada, ER20	Low-Risk Ankle Rule sensitivity 100% (93.3% to 100) specificity NR ITS	2151, children aged 3–16, emergency departments of six hospitals	Phase 1: no intervention Phase 2: educational interventions to encourage CPR use (ie, physician education, pocket cards, posters) and CDSS Phase 3: CDSS only Comparison: usual care	Physician behaviour: referral for ankle X-ray	Relative reduction in ankle X-rays in intervention sites compared to control sites. RR: 21.9% (95% CI 15.2% to 28.6%)
Stiell, 1997, Canada, ER17	Ottawa Knee Rule; sensitivity 100% (94% to 100), specificity 49% (46% to 52%) Controlled before-after	3907, ≥18 years, emergency departments of 4 hospitals (2 community and 2 teaching)	Intervention: educational interventions to encourage CPR use (ie, lecture, pocket cards and posters). Comparison: Usual care	Physician behaviour: referral for knee radiography	Relative reduction of 26.4% of patients referred for knee X-ray in intervention group (77.6% vs 57.1% (p<0.001), vs relative reduction of 1.3% in control group (76.9% vs 75.9%, p=0.6)
Stiell, 2009, Canada, ER18	Canadian C-spine Rule sensitivity 99% (96% to 100%), specificity 45% (44% to 46%) Cluster RCT	11 824, ≥16 years, emergency departments of 6 hospitals	Intervention: educational interventions to encourage CPR use (ie, lecture, pocket cards and posters) and CDSS at point of requesting imaging Comparison: usual care	Physician behaviour: diagnostic imaging rate of cervical spine	Relative reduction of 12.8% for cervical spine imaging (95% CI 9% to 16%) intervention group. Control group showed a relative increase of 12.5% (95% CI 7% to 18%)
McIsaac, 2002, Canada, Primary care29	McIsaac Sensitivity 83% (no CIs), specificity 94% (no CIs) RCT	621, ≥3 years, general practice, 97 participating GPs	Intervention: mailed educational intervention (published score with summary explanation with pocket card). Physicians were provided with a sticker to apply to the encounter form that listed the score and management approach. Comparison: physicians only received the education material.	Physician behaviour: unnecessary antibiotic prescriptions (negative throat swab)	Non-significant difference intervention vs control groups in unnecessary antibiotic prescription (20.4% vs 16.1%, p=0.29)
McIsaac, 1998, Canada, Primary care28	Centor score sensitivity 90% (no CIs), specificity 92% (no CIs) RCT	396, ≥15 years, general practice, 450 participating GPs	Intervention: mailed CPR with summary explanation and patient information. Physicians asked to complete an encounter form. Comparison: mailed educational intervention and a control form with no score or management actions.	Physician behaviour: antibiotic prescription	Non-significant reduction in antibiotic prescription in intervention group (27.8%) vs control (35.7%) (p=0.09)
McGinn, 2013, USA32	Walsh rule for streptococcal pharyngitis Heckerling rule for pneumonia Walsh rule: c-statistic: 0.71 (95% CI 0.67 to 0.74) Heckerling rule: c-statistic 0.82 (0.74 to 0.9) RCT	168 Primary care providers, 2 large academic ambulatory care centres in New York	Intervention: education session and computerised CDSS with CPRs embedded promoting physician to calculate scores of both CPRs and receive management recommendations. Comparison: usual care with background information on CPRs	Physician behaviour: change in antibiotic prescription	Intervention group significantly less likely to order antibiotics than control (age-adjusted RR, 0.74; 95% CI 0.60 to 0.92). Absolute risk difference 9.2%.
Worrall, 2007, Canada30	Modified Centor score sensitivity 90% (no CIs), specificity 92% (no CIs) RCT	533, ≥19 years, 37 practices in eastern Newfoundland CPR:170 RADT: 120 RADT+CPR:102 Control:141	CPR group: decision rules only RADT group: rapid antigen test only RADT+CPR group: decision rules and antigen test combined Comparison: usual care	Physician behaviour: prescribing rate of antibiotics	Prescription rates: CPR alone—55% RADT—27% (NS) RADT+CPR—38% (p<0.001) Control: 58%
Little, 2013, UK31	Fever PAIN c-statistic: 0.71 RCT	631, ≥3 years, general practice (48 UK practices)	CPR group: CPR was applied and antibiotic prescribed according to the score. CPR+RADT group: CPR was applied and antibiotic prescribed or RADT carried out according to the score. Comparison: Delayed prescribing	Patient behaviour: patient-reported symptom severity days 2–4 after consultation on a 7-point Likert scale	Greater improvements in symptom severity for CPR group compared to control (−0.33, 95% CI −0.64 to −0.02)
Pozen, 1984, USA, ER21	Pozen score for chest pain sensitivity 94% (no CIs), specificity 78% (no CIs) ITS	2320, aged ≥30 male and ≥40 female, emergency departments of 6 US hospitals	Intervention: research assistant presented physicians with the CPR probability score. Comparison: usual care, the CPR probability was calculated but not presented to the physicians.	Physician behaviour: appropriate admission/discharge	30% relative reduction in patients admitted to CCU who did not have acute coronary syndrome
Kline, 2009, USA, ER22	Kline chest pain CPR c-statistic 0.74 (0.65 to 0.82) RCT	369 adults presenting with chest pain, one emergency room in an academic urban US hospital	Intervention: clinicians and patients received a printout of CPR result displayed numerically and graphically. Comparison: usual care, no printout was provided to clinicians or patients.	Physician behaviour: hospital admission with no significant cardiovascular diagnosis	No significant decrease for patients admitted with no CVD diagnosis: 11% vs 5% (95% CI −0.2% to 11%), p=0.059
Persell, 2012, primary care27	Framingham risk estimate and global cardiovascular risk score Cluster RCT	N=14 physicians, n=218 adult patients randomised to intervention, n=15 physicians, n=217 adults patients randomised to control, US primary care	Intervention: individualised CVD risk estimate posted to high-risk patients and their physicians alerted by secure email Control: usual care	Patient: reduction in LDL-cholesterol level by 30 mg/dL	No difference in the primary outcome (11% vs 11.1% OR 0.99, 95% CI 0.56 to 1.74, p=0.96) but intervention patients were more likely to receive a prescription for a statin (11.9% vs 6%, OR 2.13, 95% CI 1.05 to 4.32, p=0.038)
Grover 2007 and 2008, primary care25 26	Framingham risk score RCT	N=3053 adults mean age 56.4, male 66.9%, n=230 primary care physicians, 10 provinces in Canada primary care	Intervention: patients identified as high risk and randomised to intervention had their individualised coronary risk profile discussed Control: usual care, coronary risk profile withheld	Patient outcomes: Reduction in LDL-cholesterol level Reduction in BP	Statistically significant reduction in LDL and total cholesterol-HDL ratio in intervention vs control and patients were more likely to reach lipid targets Patients in intervention group were more likely to receive appropriate antihypertensive treatment and more likely to start or modify treatment
Hall, 2003, UK23	New Zealand cardiovascular risk score NR Pilot RCT	323, aged 35–75 years, patients with no history of cardiovascular or renal disease, one UK hospital outpatient department (OPD) clinic	Intervention: risk scores were clearly documented at the front of the notes of patients. Comparison: usual care	Physician behaviour: Prescription of risk-modifying drugs Management of CVD risk factors	No significant between-group differences: change in diabetes treatment 42% (95% CI 34% to 50%) vs 58 (95% CI 29% to 45%), change in antihypertensive drugs 26 (95% CI 10% to 22%) vs 10% (95% CI 5% to 16%), change in lipid lowering drugs: 12% (7% to 17%) vs 9% (95% CI 4% to 14%) Referral to dietician 10% (95% CI 6% to 15%) vs 13% (95% CI 7% to 19%)
Hanon, 2000, France24	Framingham risk score NR RCT	1243, aged 18–75 years with hypertension attending a general physician	Intervention: physicians knowledge of the calculated risk score. Comparison: usual care	Patient and Physician behaviour: change in BP, patients prescribed dual therapy	No difference in BP (patients with BP <140/90 mm Hg intervention: 64%, control 62%) or % patients on dual therapy (41% intervention vs 46% control)
Stiell, 2010, Canada, ER33	CT head rule sensitivity 100% (96% to 100%), specificity 51% (48% to 53%) Cluster RCT	4531, alert and stable adults with minor head injury aged ≥16 years, 12 emergency departments in three provinces of Canada (6 teaching sites, 6 community sites)	Intervention: educational interventions to encourage CPR use (ie, lecture, pocket cards and posters) and real-time reminder at point of requesting imaging Comparison: usual care	Physician behaviour: proportion of patients referred for CT imaging	Increased proportion of patients referred for CT imaging intervention: before: 62.8%, after: 76.2% (difference: 13.3% (95% CI 9.7% to 17.0%) Control: before: 67.5%, after: 74.1% (difference: 6.7% (95% CI 2.6% to 10.8%)

CPR, clinical prediction rule; NA, non-applicable; NR, not reported; NS, non-significant.