Systematic Reviews
Copyright ©The Author(s) 2015.
World J Gastroenterol. Apr 28, 2015; 21(16): 5056-5071
Published online Apr 28, 2015. doi: 10.3748/wjg.v21.i16.5056
Table 1 Summary table of all competency research regarding medical and nurse and other non-physician endoscopists
PublicationSettingNon-physician proce-duresSupervisionTrue randomization of patients?ProceduristsPotential biasesOutcome parametersModalityOutcome
Rosevelt et al[8], 1984Metropolitan Tertiary Centre, United States825YesNo1 NEPatient selection biasEndoscopist selection biasLevel of assistance not documentedPolyp detection rateComplicationsFSPolyp detection rate of 8.7%No complications
Schroy et al[4], 1988Metropolitan Tertiary Centre, United States100YesNo1 NEPatient selection biasEndoscopist selection biasLevel of assistance not documentedConcordance criteria not givenPolyp detection rateConcordance of findings with expert opinionFSPolyp detection rate of 36%Video review showed k = 0.72 concordance with GCNurse sensitivity = 75%, specificity = 94%
DiSario et al[15], 1993Metropolitan Tertiary Centre, United States80YesYes5 NEs5 GRsEndoscopist selection biasLevel of assistance not documented1 NE excluded due to incompetency after trainingComparison of outcome groups for missed lesions not calculatedInsertion depthIdentification of anatomyComplicationsProcedure timeMissed lesionsFSPolyp detection rate of 24%Insertion depth, complications and procedure time similar between groupsNEs missed more lesions and missed more anatomy
Maule[7], 1994Metropolitan Tertiary Centre, United States1881YesNo4 NEs2 GCsEndoscopist selection biasComplicated patient referred away from NEsLevel of assistance not documentedInsertion depthComplicationsPolyp detection ratePatient satisfactionFSGCs had significantly deeper insertion depthsSimilar polyp detection rateSimilar patient satisfaction
Moshakis et al[16], 1996Metropolitan Tertiary Centre, United Kingdom50YesNo1 NE1 GCEndoscopist selection biasPatient selection biasNE was compared to GC who performed trainingLevel of assistance not documentedMethod of quality scoring not givenInsertion depth“Quality and accuracy”FSInsertion depth, quality and accuracy were similar between comparison groups
Duthie et al[6], 1998Metropolitan Tertiary Centre, United Kingdom205Not specifiedNo1 NEEndoscopist selection biasPatient selection biasCriteria for “successful procedure” not givenSuccessful procedure when compared to various other imaging modalitiesFS93% of procedures considered “successful”
Schoenfeld, Cash et al[17], 1999Metropolitan Tertiary Centre, United States114YesNo1 NE3 GFs3 Surgical ConsultantsEndoscopist selection biasPatient selection biasLevel of assistance not documentedDepth of insertionProcedure timePolyp detection ratePatient satisfactionComplicationsFSSurgeons had less depth of insertion than NEs or GFsNEs had longer procedures than GFs or surgeonsPolyp detection rate similarNo complications
Schoenfeld, Lipscomb et al[10], 1999Metropolitan Tertiary Centre, United States151YesYes3 NEs4 GCsEndoscopist selection biasPatient selection biasLevel of assistance not documentedHigh threshold for detecting difference in polyp detection ratePolyp detection rateDepth of insertionComplicationsFSPolyp detection rates similar between groups (43%-45%)GCs had much greater depth of insertionNo complications
Wallace et al[9], 1999Metropolitan Tertiary Centre, United States2323YesNo1 NE2 PAs15 GCsEndoscopist selection biasPatient selection biasLevel of assistance not documentedDepth of insertionPolyp detection rateComplicationsFSGCs had significantly greater depths of insertion compared with NE+PAsPolyp detection rate similar between groups (23%-27%)No complications
Schoen et al[26], 2000Metropolitan Tertiary Centre, United States660Not specifiedNo1 PE1 GC1 MCEndoscopist selection biasPatient selection biasLevel of assistance not documentedPatient satisfactionFSSimilar patient satisfaction between groups
Shapero et al[27], 2001Metropolitan Tertiary Centre, Canada488NoNo2 NEsEndoscopist selection biasPatient selection bias Level of assistance not documentedPolyp detection rateComplicationsDepth of insertionProcedure timeFSAverage depth of insertion 52.9 cm8.4 min average procedure timePolyp detection rate of 15.4%
Jain et al[28], 2002Metropolitan Tertiary Centre, United States5000NoNoNot specifiedNo physiciansUnknown endoscopistsPatient selection biasLevel of assistance not documentedNo comparisonPolyp detection rateNo complicationsFSNo major complications polyp detection rate of 13.3%
Meenan et al[29], 2003Metropolitan Tertiary Centre, United Kingdom25YesNo1 NE4 GFsEndoscopist selection biasPatient selection biasLevel of assistance not documentedViews by NE were limited to the esophagusAdequacy of views obtain by radial ultrasound by endoscopyEGDNEs had consistently lower quality scores
Smale et al[30], 2003Metropolitan Tertiary Centre, United Kingdom1487YesNo2 NEs15 mixed medical/surgical physiciansEndoscopist selection biasPatient selection biasLevel of assistance not documentedComplicated patients excludedRetrospective and prospectiveDifferences in sedationPatient satisfactionEGDNo difference between groups for sedation or patient satisfactionSubjectively, nurses reporter fewer studies as normal
Wildi et al[22], 2003Metropolitan Tertiary Centre, United States40YesNo1 NE1GCEndoscopist selection biasPatient selection biasLevel of assistance not documentedMethod of assessment not givenConcordance of findings with GCEGDNE had sensitivity of 75% and specificity of 98% with GC as gold standard
Nielsen et al[12], 2005Metropolitan Tertiary Centre, Denmark69YesNo2 NEsUnknown number of physiciansEndoscopist selection biasPatient selection biasLevel of assistance not documentedPatient satisfactionFSNurses had better patient satisfaction than physicians
Meining et al[3], 2007Metropolitan Tertiary Centre, United Kingdom190YesYes2 NEs1 GC2 GRs1 Physician not specified1 MCEndoscopist selection biasPatient selection biasLevel of assistance not documentedSubjectivey, nurses tended to focus on the entire examination whilst physicians focused on the reason for referralAdequacy of views for entire procedureDuration of procedureUse of sedationEGDNurses had twice the amount of adequate views however took twice as long on average.Nurses used sedation more frequently
Williams et al[19], 2006 Williams et al[21], 2009Nation-wide Metropolitan Tertiary Centres, United Kingdom957YesYes30 NEs67 physicians (not specified)Significantly higher numbers of patients changed schedule from physician to nurse (duePatient satisfactionAdequacy of viewsDepth of insertionEndoscopic procedures performedDuration of examinationComplicationsEGDPatient satisfaction favoured nursesNo difference for depth of insertionNurses took biopsies for histology in upper endoscopy and FS more frequently than physicians.There were more normal histology findings for nurses
Richardson et al[20], 2009Need for assistanceNeed for subsequent follow up and investigationCost-benefit analysisNurses were more likely to report sedation and procedural details whilst physicians were more likely to report diagnosis and suggested treatment.Nurses took biopsies for H. pylori more frequentlyNo major differences in final diagnoses frequency between 2 groups.No serious complicationsSimilar need for assistance.Nurses had greater follow-up cost per procedure whilst physicians had greater labor costs per procedure.Physicians had greater overall costs per procedure but greater patient improvement.Physicians were 87% more likely to be cost-effective than nurse endoscopists.
Koornstra et al[11], 2009Metropolitan Tertiary Centre, Netherlands300YesNo2 NEs1 GF1 GCEndoscopist selection biasPatient selection biasLevel of assistance not documentedCaecal intubation rateCaecal intubation timeComplicationsPatient satisfactionColSimilar caecal intubation rates/times (80%-90%) between GF and NEs but much lower/longer than GC after 150 procedures.Patient satisfaction similar between GF and NEs, less than for GC.Similar complication rate.
Maslekar, Hughes et al[31], 2010Metropolitan Tertiary Centre, United Kingdom308Not specifiedNo1 NE1 PA/TSeveral physicians not specifiedEndoscopist selection biasPatient selection biasLevel of assistance not documentedNE and PA/Ts had less colonoscopies more FSComplicationsPatient satisfactionCol and FSNo difference between all 3 groups
Maslekar, Waudby et al[32], 2010Metropolitan Tertiary Centre, United Kingdom26YesNo1 Surgical Registrar1 PA/TEndoscopist selection biasPatient selection biasLevel of assistance not documentedPatients needing resection excludedAccuracy of endoscopists to gauge position in colonFSPA/T accuracy of 70% with Registrars accuracy of 80%, not statistically significant.
Shum et al[18], 2010Metropolitan Tertiary Centre, HK119YesNo1 NENo comparison groupMean procedure timeDepth of insertionComplicationsFS9.4 min average procedure time53.5 cm average depth of insertionNo major complications
Limoges-Gonzalez et al[44], 2011Metropolitan Endoscopy Centre, United States50YesYes1 NE2 GCsEndoscopist selection biasLevel of assistance not documentedAdenoma detection rateCaecal intubation rateCaecal intubation timePatient satisfactionSedation useComplicationsColAdenoma detection rate higher in NE (42%) than GCs (17%)All other parameters similar across both groups
de Jonge et al[33], 2012Multi-metropolitan tertiary centre, Netherlands162Not specifiedNo (retrospective)6 NEs113 Staff not specified including GCs, GFs, surgeons, MCsData was retrospective review of reportsOverall caecal intubation rateAdenoma detection rateColNEs and GFs and GCs found more adenomas and had greater caecal intubation rates (94%) than nongastroenterology staff, especially surgical
van Putten et al[34], 2012Multi-metropolitan tertiary centre, Netherlands1000YesNo10 NEsEndoscopist selection biasPatient selection biasUnassisted caecal intubation rateWithdrawal timeAdenoma detection rateAssistance requirementsPatient satisfactionComplicationsColUnassisted caecal intubation rate of 94%23% of colonoscopies required assistance from GCWithdrawal time of 10 minAdenoma detection rate of 23%1 perforation and 1 onset of atrial fibrillation95% of patients satisfied with procedure
Massl et al[5], 2013Multi-metropolitan tertiary centre, Netherlands866YesNo7 NEs8 GFsEndoscopist selection biasNEs had significantly lower ASA scores on patientsLevel of assistance not reportedUnassisted caecal intubation rateCaecal intubation timeComplicationsPolyp detection rateColUnassisted caecal intubation rate was significantly lower 77% for NE than GFs (88%).Polyp detection rate (45%), complications, withdrawal and intubation times were similar between groups.Crude cost-analysis showed a saving of €7.61 per colonoscopy where 1 GC supervises 3 NEs. Did not account for higher need for repeat colonoscopies due to incomplete procedures
Table 2 Assessment of the risk of bias assessments for studies included into this systematic review and key characteristics of data analysis
PublicationSequence generationAllocation concealmentBlinding of participants, personnel and outcome assessorsIncomplete outcome dataSelective outcome reportingOther sources of biasStudy hypothesis and power calculation
Rosevelt[8], 1984No randomizationNoNoNot specifiedLikely, report was intended to describe a successful training programNo hypothesis, no statistics
Schroy et al[4], 1988No randomization, review of videotapeNoNoNot specifiedReport of an established service model. Review of videotapes Quality assuranceNo statistics
DiSario[15], 1993Computer generated randomizationNot specifiedNoNot specifiedAim was to demonstrate that “.registered nurses could be trained to perform the flexible sigmoidoscopy in a similar to resident physicians’Not powered to demonstrate equivalence, no formal power calculations
Maule[7], 1994No randomizationNot specifiedNoNot specifiedThe study was done to confirm that training of nurse endoscopists is feasible.Hypothesis defined (no difference), no power calculation for equivalence study, oucome parameters not specified a priori
Moshakis et al[16], 1996No randomization, no comparatorNot specifiedNoNot specifiedReport describes the successful training of one (1) nurse endoscopistNo hypotheses, no statistical analysis
Duthie et al[6], 1998No randomizationNoNoNot specifiedEvaluation of a training program that was developed and implemented by the authors (self-fulfilling prophecy)Not evidentNo hypothesis, no power calculation
Schoenfeld et al[17], 1999No randomization, patients allocated to the ‘first available provider’NoNoNot specifiedNo evidenceNot evidentSeveral outcome parameters specified, but no hypothesis tested, no power calculation for equivalence.
Schoenfeld et al[10], 1999Randomization of veterans referred for flexible sigmoidoscopy. Computer generated randomizationNounknownNot specifiedJustifies the implemented clinical service model.Several outcome parameters listed, but no specific hypothesis, power calculation provided (to identify differences, but not targeting equivalence)
Wallace et al[9], 1999No randomization, nurse-coordinator assigned eligible patients to a physician or non-physician endoscopists based upon ‘daily staffing assignments and patient time preference’NoUnknownNot specifiedJustifies the implemented clinical service model.No hypothesis stated, no power calculation
Schoen et al[26], 2000No randomizationNoNoNot specifiedStudy targeted to demonstrate the good tolerability of flexible sigmoidoscopyGender distribution of patients was not equivalent across examiners, and the nurse practitioner did not have trainees working with her.No hypothesis stated, no proper power calculation
Shapero et al[27], 2001No randomization, allocation not clearNoNoNot specifiedData justify the implemented clinical practiceData are generated in the setting of CRC screening with flexible sigmoidoscopy, highly selective cohort.Not done
Jain et al[28], 2002No randomizationNoNoNot specifiedJustification of implemented clinical practiceCRC screening utilizing flexible sigmoidoscopy, selective cohortNot done
Meenan et al[29], 2003No randomizationNoNoNot specifiedAssessement of training progressNot done
Smale et al[30], 2003No randomization, part one retrospective analysis of endoscopy data base, second part prospective data collectionNoNoNot specifiedReview and justification of clinical practiceNot done
Wildi et al[22], 2003No randomizationNoNoNot specifiedSequential procedures Nurse endoscopist followed by physyician, potential effect of sequence.Not done
Nielsen et al[12], 2005No randomizationNoNoNot specifiedQuality assurance of existing training programNot done
Meining et al[3], 2007No details in relation to the randomization process are provided. Patients unequally allocated to endoscopist or nurseNoNoReported but uneven numbers of ‘Randomization failures (33 vs 0). Considerable number of patients excluded (only 367 out of 641 reported)Review and justification of clinical practicePrimary outcome parameter was stated as “appropriate diagnosis”, this outcome parameter was not reported.Not done
Williams et al[19], 2006 Williams et al[21], 2009 Richardson et al[20], 2009Randomization of patients to nurse or physician endoscopyNoNoProperly reportedPrimary outcome parameter not related to endoscopic. Measured with Gastrointestinal Symptoms Rating scale up to one year after procedureOnly patients suitable to be serviced by nurse endoscopists included. Numerically more patients from the nurse cohort were lost of follow-up without specified reasons (286 vs 269). A trend for more patients with weight loss in the physicians cohort, more patients in the physicians’’ cohort had previously barium enema (suggesting more chronic or relapsing symptoms)Authors make reference to required sample sizes. Total number of patients completed was below the required sample size
Koornstra et al[11], 2009It is stated that patients were randomly allocated, no information is given on allocation. Proportion of inpatients lower in the nurse group. No evidence for ethic approval or consent of patients. Training of nurse and medical staff was not identicalNoNoNo information providedMultiple endpoints reportedThe authors developed a training program and with their data they aimed to confirm that their training program delivered (self-fulfilling prophecy).Not powered to verify equivalence
Maslekar et al[31], 2010Patients were allocated by administrative staff into the nurse or medical specialist group.NoNoIncomplete response data cited as reason for exlusion (48/561 excluded), no intention to treat analysisStudy justifies an implemented service model that aims to address shortage of medical specialistsThe instrument was unlikely to detect group differences. Variable mixture of flexible sigmoidoiscopy and colonoscopy across groupsNo power calculation
Maslekar et al[32], 2010No randomizationNo information givenNoNot reportedJustifies implemented service and training modelFor flexible sigmoidoscopies the validity of the endoscopists impression of maximal extension was tested. A priori unlikely to identify difference.No power calculation
Shum et al[18], 2010No randomizatiom, no comparatorNoNoNo information providedJustifies the implemented training modelNo
Limoges-Gonzalez et al[44], 2011It is stated that patients were randomly allocated, no information is given on allocation.NoNoNo information providedJustifies the implemented service modelPostprocedure questionnaire was administered after (at least) 30 min of recovery. Drug effects likely to blunt potential differencesNo power calculation
de Jonge et al[33], 2012Routine quality data were used, no randomization.NoNoNo information providedData were partly retrospective data, partly prospective data, no justification given.?No power calculation
van Putten et al[34], 2012Allocation of patients by secretatial staff, no randomizationNoNot reportedNot specifiedJustifies and implemented service modelSignificant differences in comorbidities (more severe in the Gastroenterologists group), differences in source of referral. Outcome assessment limited to immediate salary comparisons not total costs including pathology and follow-up.No power calculation
Massl et al[5], 2013It is stated that patients allocated by administrative staff, endoscopists assigned to lists randomly based on availabilityNoNo79/2025 procedures not included due to drop out of 1 nurse endoscopist for unspecified reasonsJustifies the implemented service modelPatients younger than 18 years or referred for therapeutic procedures were excluded from the nurse endoscopist group only. Drop out of nurse endoscopist not justified.Power calculation done.Appropriate numbers achieved.