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Why Do Physicians Not FollowEvidence-Based Guidelines forPreventing Ventilator-AssociatedPneumonia?*A Survey Based on the Opinions of an InternationalPanel of Intensivists

Jordi Rello, MD, PhD; Carmen Lorente, MD; Maria Bodı, MD; Emili Diaz, MD;Maite Ricart, RN; and Marin H. Kollef, MD, FCCP

Objective: Adherence to clinical practice guidelines is highly variable. Our objective was toreview barriers to physicians’ adherence to evidence-based guidelines (EBGs) for preventingventilator-associated pneumonia (VAP).Methods: A questionnaire was administered to 110 opinion leaders on VAP from 22 countries toindicate whether 33 pharmacologic and nonpharmacologic practices that had been listed in arecent publication had been implemented in their ICUs. If these prevention strategies were notused, the respondents were asked to indicate one of seven reasons for nonadherence, with theobjective of identifying barriers to adherence to EBGs.Results: The overall nonadherence rate was 37.0%. The nonadherence rate was 25.2% forstrategies recommended for clinical use, compared with 45.6% for strategies with less effective-ness (odds ratio [OR], 1.80). Pharmacologic strategies had a higher degree of nonadherence thannonpharmacologic strategies (OR, 2.92). Nonadherence to recommendations graded A, B, C, D,and U based on an objective assessment of the consistency of the supporting evidence was 41.3%,35.7%, 16.0%, 45.7%, and 20.8%, respectively. The most common reasons for nonadherence werethe following: disagreement with interpretation of clinical trials (35%); unavailability of resources(31.3%); and costs (16.9%).Conclusion: We conclude that nonadherence to EBGs for preventing VAP was common andlargely uninfluenced by the degree of evidence. A rational approach toward improving VAPguideline adherence should take into account the heterogeneous factors that influence physicianadherence to them. (CHEST 2002; 122:656–661)

Key words: evidence-based guidelines; ICU; nonadherence; prevention; ventilator-associated pneumonia

Abbreviations: EBG � evidence-based guideline; VAP � ventilator-associated pneumonia

T he Centers for Disease Control and Preventionhas been developing evidence-based guidelines

(EBGs) for the prevention and control of nosocomialinfections since the early 1980s. Clinical practiceguidelines aim to improve the quality of care, to

decrease costs, and to reduce inappropriate variationin decision making in this setting.1–3 The develop-ment of EBGs should be based on multidisciplinary

*From the Critical Care Department (Drs. Rello, Lorente, Bodı,and Diaz, and Ms. Ricart), University Hospital Joan XXIII,University Rovira and Virgili, Tarragona, Spain; and the Pulmo-nary and Critical Care Division (Dr. Kollef), Washington Univer-sity School of Medicine, St. Louis, MO.

This study was supported by Comisio Interdepartamental deRecerca i Innovacio Technologica (grant No. 2000-SGR-128) andDistincio per la Promocio de la Recerca Universitaria.Manuscript received August 13, 2001; revision accepted Febru-ary 13, 2002.Correspondence to: Jordi Rello, MD, PhD, Critical Care Depart-ment, University Hospital Joan XXIII, Dr Mallafre Guasch, 4,E43007 Tarragona, Spain; e-mail: [email protected]

clinical investigations in critical care

656 Clinical Investigations in Critical Care

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participation and should incorporate methods theefficacy and cost-effectiveness of which are sup-ported by evidence-based clinical studies.4,5

Despite the rise in evidence-based medicine andthe existence of clinical practice guidelines of provenutility, the use of these guidelines in daily clinicalpractice is still limited. Rates of adherence to guide-lines are variable, ranging from 20% to nearly 100%,depending on the guideline.1 Moreover, the degreeof evidence in favor of a strategy does not alwaysguide practice.1,2 Despite the fact that physicianadherence to guidelines is critical to their ultimatesuccess, there have been few published studies of thefactors that influence such adherence.

To help prevent ventilator-associated pneumonia(VAP), several resources and strategies are available.Airway management is an important variable influ-encing the development of VAP.4 Kollef5 has iden-tified 33 potentially useful strategies for the preven-tion of VAP. These strategies were taken from asystematic review of the literature, and the appropri-ate value of each recommendation was judged withrespect to consistent methodological standards. AFranco-Canadian survey6 reported that such preven-tion guidelines were used in 64% and 30% of theirICUs, respectively (p � 0.01). Decisional responsi-bility for each strategy differed among institutions.In addition, despite a large amount of evidenceregarding the beneficial effects of hand washing andother infection control practices, studies in the liter-ature have repeatedly documented that the impor-tance of these procedures has not been sufficientlyrecognized by health-care workers,7 and compliancewith hand-hygiene practices and other infectioncontrol measures is unacceptably low.7,8

The factors that influence physicians’ adherence toguidelines are likely to vary. Therefore, we per-formed an investigation with two main goals. Thefirst goal of this study was to determine the level ofcompliance with EBGs for the prevention of VAPamong an international panel of critical care clini-cians. Our second objective was to identify thereasons for noncompliance with these EBGs. It wasour intention that these data would assist in under-standing how clinicians make decisions regarding theimplementation of EBGs in the ICU setting. Moreimportantly, such information also could be used indeveloping future programs that are aimed at moreeffectively implementing EBGs.

Materials and Methods

We prepared a questionnaire that assessed 33 potential strat-egies for preventing VAP. The interventions examined on thequestionnaire and the recommendation for clinical use (ie,effective, ineffective, or strategies of equivocal or undetermined

effectiveness) were taken directly from the review article byKollef.5 The items listed in Tables 3 and 4 are taken directly fromthis publication.

We asked all physicians who had previously been selected andinvited to attend an international symposium on therapy for VAP,which was held in Barcelona on May 20 to 21, 2000, to answer thequestionnaire. All participants were physicians working as inten-sivists and ICU directors in Europe, Asia, Africa, South America,and the United States. These clinicians were identified as beinglocal opinion leaders in the management of ICU-acquired infec-tions, including VAP. These clinicians had at least 5 years ofexperience working in ICUs. The session participants respondedto the questionnaire without prior knowledge at the meeting ofthe recommendations for clinical use and the degree of evidencefor each intervention as reported by Kollef.5

If these prevention strategies had not been used, the respon-dents were asked to indicate one of seven reasons for non-adherence. Only the most important reason was considered foranalysis; the seven different possibilities for nonadherence topreventive strategies were as follows: disagreement with theresults of previous studies; unavailability of resources; adverseeffects; high costs; patient discomfort; convenience for nurs-ing; and other unspecified causes. Participants answeredanonymously but were asked to indicate their primary medicalspecialty and country of origin.

All the strategies included in the questionnaire were backed upby studies of varying degrees of scientific-based evidence. Studieswere graded as follows: those supported by two randomized,controlled investigations were classified as “degree of evidenceA”; those supported by at least one randomized, controlledinvestigation were classified as “degree if evidence B”; thosesupported by nonrandomized, concurrent-cohort investigations,historical-cohort investigations, or case series as were classified“degree of evidence C”; those supported by randomized, con-trolled investigations of other nosocomial infections were classi-fied as “degree of evidence D”; and those undetermined or notyet studied in clinical investigations were classified as “degree ofevidence U”. The review manuscript5 recommended some of theprocedures, while others were deemed less effective and, hence,were not recommended.

Results

The survey was answered by 62 of the 110 physi-cians (56.4%) who were approached. Their countriesof origin are shown in Table 1. Overall, 54.8% ofresponders were from member countries of theEuropean Union. Other European countries repre-sented 30.6% of responders, and 8% of responderswere from South America. Russia was representedby four physicians, the Middle Orient was repre-sented by two physicians, South Africa was repre-sented by one physician, and North America by onephysician. Their primary specialties were the follow-ing: critical care (33 physicians); anesthesiology (10physicians); critical care and anesthesiology (5 phy-sicians); critical care and respiratory (6 physicians);respiratory (3 physicians); internal medicine (29physicians); infectious disease (2 physicians); andsurgery (1 physician). All of these experts spent atleast 25% of their time in the care of critically illpatients in an ICU setting.

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The overall rate of nonadherence was 37.0%. Forstrategies recommended for clinical use (as used byKollef5 to identify more clinically useful strategies),the nonadherence rate was 25.2%, compared with45.6% (odds ratio, 1.80) for strategies classified asbeing less effective. This difference was due to atwofold increase in the percentage of nonadherencefor pharmacologic measures classified as being inef-fective or of equivocal effectiveness compared withthose classified as being effective (78.9% vs 38.9%,respectively). Pharmacologic strategies had a signif-icantly higher degree of nonadherence (odds ratio,2.92) compared with nonpharmacologic strategies(57.4% vs 19.6%, respectively). In contrast, similarpercentages were documented for nonpharmaco-logic strategies that were recommended for clinical

use compared with those with less effectiveness(16.4% vs 23.4%, respectively).

The correlation between the degree of evidenceand the rate of adherence to the EBGs is shown inTable 2. Nonadherence with recommendationsgraded A, B, C, D, and U based on an objectiveassessment of the consistency of the evidence was41.3%, 35.7%, 16.0%, 45.7%, and 20.8%, respec-tively.

Physicians’ reasons for nonadherence and therates of nonadherence are shown in Tables 3 and 4.Overall, the most important barriers to adherencewere the following: disagreement with the interpre-tation of reported trials (35%); the unavailability ofresources (31.3%); high costs (16.9%); nursing con-venience (3.7%); fear of potential adverse events(2.2%); potential patient discomfort (0.8%); andmiscellaneous indications for nonadherence (9.7%).

Discussion

Little is known about barriers to physicians’ adher-ence to clinical practice guidelines. There is veryscarce information, to our knowledge, to assess whyphysicians may not follow EBGs for preventing VAP.We assessed six potential barriers and found themost important to be disagreement with the inter-pretation of reported trials and lack of resources. Incontrast, potential patient discomfort, adverse ef-fects, and convenience for nursing staff were rarelymentioned.

In 2000, a Franco-Canadian survey6 evaluated theuse of ventilator circuits and secretion managementby ICU directors. A unique feature of our study isthe inclusion of physicians with an internationalfocus, representing 22 different countries. In addi-tion, we incorporated the role of broader infectioncontrol issues in our questionnaire. Consistent withthe findings of Cook et al,6 factors other than thedegree of evidence in support of specific strategiesappeared to be the important barriers to their ad-

Table 1—List of Physicians by Country

CountriesPhysicians,

No.

Argentina 3Austria 4Belgium 5Czech Republic 1Colombia 1Croatia 1Estonia 2Germany 2France 6Greece 2Italy 2Portugal 1Poland 1Russia 4Saudi Arabia 2Slovenia 6South Africa 1Spain 9Sweden 3Switzerland 4Uruguay 1United States 1

Table 2—Correlation Between the Degree of Evidence and the Rate of Adherence*

Variables

Strategy Recommended for Clinical Use, % Strategy Ineffective or of Undetermined Effectiveness, %

A B C D U Overall A B C D U Overall

Implementation 11.7 80.0 84.0 65.8 0 48.3 66.5 48.5 0 8.6 79.2 40.6Disagree 16.7 7.6 4.3 9.6 0 7.4 13.8 25.8 0 39.7 6.0 17.1Not available 50.0 3.9 4.6 12.6 0 14.2 9.0 13.5 0 12.1 4.3 7.8Adverse effects 0 1.0 0.4 1.3 0 0.5 2.3 3.1 0 0 0 1.1Costs 10.0 0 0.8 5.7 0 3.3 4.1 2.7 0 31.0 5.2 8.6Patient discomfort 0 0.4 0 1.0 0 0.3 0.3 0.3 0 0 0.9 0.3Nursing convenience 3.3 3.4 2.1 0 0 1.8 0.9 2.0 0 0 0.9 0.8Other 3.2 3.8 3.8 3.9 0 2.9 3.2 4.1 0 8.6 4.2 4.0

*Disagree � disagree with the results.



herence. Pharmacologic strategies had a higher de-gree of nonadherence than nonpharmacologic ones.In fact, eight of the proven nonpharmacologic strat-egies had a rate of nonadherence of � 10%, and onlytwo proven pharmacologic strategies (ie, avoidanceof unnecessary antibiotics and use of antibiotics forneutropenic fever) had a rate of nonadherence of� 10%.

Moreover, the degree of nonadherence seems tobe independent of the strength of the evidence insupport of specific interventions that have beenreported in previous trials. There was great variabil-ity between strategies, ranging from 0 to 88.3% forstrategies with grade A evidence. The degree ofnonadherence was also independent of the grade ofeffectiveness. For instance, some strategies consid-ered to be ineffective by trials classified as “degree ofevidence A” had rates of adherence of � 50%. Thesestrategies included the following: dedicated use ofdisposable suction catheters; chest physiotherapy;routine changes of ventilator circuit; and daily

changes of heat and moisture exchangers. At theother extreme, the continuous aspiration of subglot-tic secretions, which had been found to be effectivein trials with an A degree of evidence, had a rate ofnonadherence of 88%. In this case, the most impor-tant reason for nonadherence was lack of availability.Selective decontamination, which was the only phar-macologic strategy with strong evidence (class A)against clinical use according to the report byKollef,5 was implemented by only 16% of opinionleaders, whereas 55% disagreed with this recom-mendation and based their decision on whether toimplement this technique on the circumstances ofthe individual patient. Based on these findings,interventions to improve adherence to EBGs regard-ing VAP that ignore the variety of barriers to theirimplementation are unlikely to be successful.

Our findings have broad policy implications. Stan-dard infection control procedures remain the corner-stone for the prevention of nosocomial and device-related infections. Interestingly, 78.3% of opinion

Table 3—Adherence to EBGs and Reason for Nonadherence to Nonpharmacologic Strategies*

Nonpharmacologic Strategies Grade Implementation, % D, % NA, % AE, % C, % PD, % Nurs, % Other, % NR, No.

Removal of nasogastric or endotrachealtube as soon as clinically feasible

C 100 0 0 0 0 0 0 0 1

Avoidance of unnecessary reintubation C 100 0 0 0 0 0 0 0 1Avoidance of gastric overdistension B 100 0 0 0 0 0 0 0 0Provision of adequate nutritional

supportC 95.1 1.6 0 0 1.6 0 0 1.6 1

Dedicated use of disposable suctioncatheters

A 93.1 0 1.7 1.7 1.7 0 1.7 0 4

Semirecumbent positioning of thepatient

B 91.8 3.3 1.6 0 0 0 1.6 1.6 1

Oral (non-nasal) intubation D 91.8 1.6 0 1.6 0 4.9 0 0 1Maintenance of adequate pressure in

endotracheal tube cuffC 90.0 0 5.0 0 1.7 0 3.3 0 2

Postural changes B 88.1 1.7 3.4 0 0 1.7 5.1 0 3Adequate handwashing between

patient contactsB 85.0 1.7 0 0 0 0 10.0 3.3 2

Chest physiotherapy A 83.3 3.3 8.3 0 1.7 0 1.7 1.7 2Use of a formal infection-control

programC 78.3 1.7 13.3 0 1.7 0 0 5.0 2

Humidification with head and moistureexchanger

A 77.2 1.8 10.5 1.8 3.5 1.8 0 3.5 5

Use of protective gowns and gloves B 76.7 5.0 3.3 0 5.0 0 5.0 5.0 2Scheduled drainage of condensate

from ventilator circuitsC 75.4 1.6 4.9 1.6 0 0 13.1 3.3 1

Routine changes of ventilator circuit A 71.2 15.3 5.1 0 3.4 0 1.7 3.4 3Routine changes of in-line suction

catheterB 70.9 5.5 18.2 0 3.6 0 0 1.8 7

Humidification with head and moistureexchanger with bacteriologic filter

U 70.0 6.9 8.6 0 10.3 1.7 1.7 1.7 4

Daily changes of heat and moistureexchangers

A 58.9 7.1 14.3 1.8 12.5 0 0 5.4 6

Continuous subglottic suctioning A 11.7 16.7 50.0 0 10.0 0 3.3 8.3 2Overall 80.4 3.7 7.4 0.4 2.8 0.5 2.4 2.3

*D � disagreement with results; NA � not available; AE � adverse effects; C � costs; PD � patient discomfort; Nurs � nursing convenience;NR � no response.



leaders reported that the lack of a formal infectioncontrol program was, in most cases, due to a lack ofavailability. Most interviewees agreed on the impor-tance of using protective gowns and gloves (unprov-en measures) and on the need for adequate handwashing between patient contacts (77% and 85%,respectively) to reduce the rate of acquired nosoco-mial infections in ICUs. This contrasts with repeatedreports that compliance with hand washing in theICU setting remains low.7–10 These observations,and the fact that cost was not often cited, stress theimportance of educational measures to improve theprevention of VAP and other nosocomial infections.For this reason, these prevention strategies shouldbe disseminated by an active educational process inorder to be successful in changing health-care pro-viders’ behaviors.

As for our study design, the sampling frame wasbased on a selected international group of intensiv-ists who were invited to a conference on VAP. Thestrengths of our study include the representation ofdifferent practices in different countries, which pro-vides a good baseline of the perceptions of theseprofessionals regarding various infection controlpractices and strategies to prevent hospital-acquiredpneumonia. However, we should emphasize that a biastoward responders from European countries is presentand that we cannot draw any conclusion from thissurvey on practices within specific countries.

Several other limitations of our study are worthnoting. First, the relatively small size of our samplelimited our ability to detect weak associations. Sec-ond, classifications of these measures were based on

a study published in 1999,5 and later reports couldmodify the classification of the different strategies orincrease the list of potentially useful measures. Thus,potential disagreement between expert opinion andEBGs should be interpreted with caution. It ispossible that opinion leaders were wrong as well asthat new data may have emerged changing theevidence for selected practices. Third, we did notassess the influence of experience on general atti-tudes toward preventing VAP. It is possible thatexperience may influence clinicians’ behaviors re-garding EBGs for the prevention of VAP. Fourth,although all participants were considered to beopinion leaders in their respective countries, someselection bias may exist because no objective defini-tion of opinion leaders was employed. Fifth, itremains unclear how many experts were unaware ofdata regarding a specific intervention, because thisresponse category was not explored. Finally, theimplementation of guidelines for preventing VAP is amultidisciplinary task. Thus, it would be interestingto know the opinion of other caregivers (eg, nurses,respiratory therapists, and physiotherapists), whichwe did not assess.

Other interesting follow-up studies should be un-dertaken based on our findings. For example, thisarticle reflects the opinions of responders but doesnot indicate what is actually done at the bedside. Forexample, for almost 150 years most health-careworkers (85% in our survey) have been taught thatthe most effective way to prevent cross-infection iswith hand washing before and after every patientcontact, although they do not do it.10,11 Thus, re-

Table 4—Adherence and Reasons for Nonadherence for Pharmacologic Strategies*

Pharmacologic Strategies Grade Implementation, % D, % NA, % AE, % C, % PD, % Nurs, % Other, % NR, No.

Avoidance of unnecessary antibiotics C 96.6 1.7 0 0 0 0 0 1.7 3Antibiotics for neutropenic fever D 91.5 1.7 3.4 1.7 0 0 0 1.7 3Combination antibiotic therapy U 88.3 5.0 0 0 0 0 0 6.7 2Limitation of stress-ulcer prophylaxis to

high-risk patientsB 67.8 15.3 1.7 5.1 0 0 1.7 8.5 3

Chlorhexidine oral rinse B 55.4 17.9 16.1 0 0 1.8 3.6 5.4 6Granulocyte colony-stimulating factor

for neutropenic feverD 44.1 15.3 22.1 0 10.2 0 0 8.5 3

Antibiotic-class rotation C 36.2 27.6 13.8 1.7 1.7 0 0 19.0 4Vaccines against Streptococcus

pneumoniae, Haemophilus influenzaetype b strains and influenza virus

D 35.7 19.6 25.0 1.8 12.5 0 0 5.4 6

Selective digestive decontamination A 15.5 55.2 13.8 8.6 1.7 0 0 5.2 4Prophylactic immune globulin D 8.6 39.7 12.1 0 31.0 0 0 8.6 4Acidification of enteral feeding

solutionsU 6.9 32.8 29.3 5.2 0 0 5.2 20.7 4

Routine parenteral prophylacticantibiotics for patients with coma

B 5.1 66.1 6.8 8.5 5.1 0 0 8.5 3

Aerosolized antibiotic prophylaxis B 1.7 50.8 35.6 6.8 0 0 0 5.1 3Overall 42.6 26.8 13.8 3 18.1 0.1 0.8 8.1

*See legend of Table 3 for abbreviations not used in the text.



search is also required to evaluate what is actuallydone at the bedside for the prevention of VAP. Inaddition, it would be interesting to know the rates ofcompliance with the individual strategies adhered toby the responders since these practices may not befully carried out in their own ICUs.

Finally, physicians’ practice patterns and how tochange them has been the subject of considerableresearch.12 Our findings confirm that publishedguidelines and clinical trials alone cannot be ex-pected to change practices at the bedside. Moreactive measures are needed to modify practicepatterns.13–15 Twenty years ago, Eisenberg andWilliams16 suggested six ways to change physi-cians’ behavior: education; feedback; financial re-wards; financial penalties; administrative changes;and physician participation. It is now recognizedthat interventions combining more than one strategy(eg, education plus feedback) will yield better successrates than single methods.17,18 Moreover, the best wayto influence hospital physician behavior may be toidentify a problem and then involve the most respectedstaff as champions of the intervention to gain overallsupport for its implementation.19,20

In summary, this opinion poll of experts from 22countries found nonadherence to clinical practiceguidelines for the prevention of VAP to be associatedwith a variety of factors, including the nature of thestrategy and its local availability. The most obviousbarrier to implementation of the guidelines wasdisagreement with the interpretation of reportedtrials. Therefore, successful implementation strate-gies for the prevention of VAP should take intoaccount the heterogeneous reasons that influencemedical decision making.

ACKNOWLEDGMENT: We are indebted to Montse Olona,MD, for statistical and methodological advice.

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