a diagnostic colonoscopy can be performed safely without prior consultation with a gastroenterologist , which increases efficiency and reduces delays and costs 2 
 3 
 4 . this practice of  open access endoscopy  ( oae ) has gained popularity , particularly in the western world . despite these benefits , concerns exist about improper referrals or patients referred for colonoscopy in whom the possible risks outweigh the benefits such as patients with serious comorbidities , those who are frail , and those with a limited life expectancy . in addition , improper referrals for colonoscopy may increase complications , average waiting time for services , and health care costs 5 . in many centers , standardized referral letters ( srl ) are screened by gastroenterologists to evaluate whether patients should be referred for colonoscopy , medications , and comorbidities . unfortunately , srls do not always provide accurate information ; therefore , we introduced a 7.5  min outpatient consultation ( oc ) , performed by a gastroenterologist , to ascertain key features about patients to determine if colonoscopy is warranted before authorizing the procedure . in this study , we prospectively evaluated the srl and the oc to define the differences in outcomes regarding regarding recommendations for or against colonoscopy and patient priority scheduling . in addition , the patients use of medications ( in particular , insulin and coumarin ) and comorbidities were recorded . this prospective , observational , single - center study was performed at the department of gastroenterology , deventer hospital , the netherlands . formal ethics committee review or approval was not required . between may 2012 and july 2012 , all consecutive patients referred for surveillance and diagnostic colonoscopy were de - identified and included in the analysis . two methods of identifying patients for colonoscopy were evaluated : the standardized referral letter ( srl ) and the outpatient consultation ( oc ) . standardized referral letter : the srl is a predefined list of approved indications and symptoms that warrant colonoscopy . this includes patients use of anticoagulants , a diagnosis of diabetes , with or without insulin therapy , and contagious diseases . all srls were scrutinized by an independent gastroenterologist who was instructed to use only the srl for authorization of colonoscopies . in instances where authorization for a colonoscopy was approved , the gastroenterologist determined the patient s priority for undergoing the colonsocopy : a , within one week ; b , within two weeks ; and c , first regular opportunity ( usually within 3    4 weeks ) . gastroenterologists were selected using a day - by - day rotation system , ensuring that they had no previous contact with the study patients or their medical records . outpatient consultation : every outpatient referred for colonoscopy had a standard 7.5  min face - to - face consultation with a gastroenterologist who verified the data in the patient s srl . the outpatient consultation occurred before and in addition to colonoscopy , but without a physical examination . additional information regarding patient symptoms , comorbidities , and use of medications was obtained from the patient and the electronic medical record system . when a colonoscopy was authorized , a priority level was given for that patient , and the patient met with a nurse for additional information about the procedure . when colonoscopies were not authorized for a patient , both the patient and the referring physician were informed by the gastroenterologist that the patient did not meet the criteria for the procedure . secondary outcomes were the differences in the patient s priority for colonoscopy , the number of malignancies identified , the number of advanced neoplastic lesions identified , and the number of new diagnoses of inflammatory bowel disease ( ibd ) . in addition , the completeness of the srl with respect to the patient s use of medications ( insulin and coumarins ) and their important comorbidities were recorded . important comorbidities were defined as previous abdominal surgery , cardiac disease , chronic obstructive pulmonary disease , malignancies , and coagulation disorders . the number of patients in this study ( 255 ) was determined by the following calculation ( because no data were available in the literature ) : power of 90  % , <  0.05 , and an estimation of 3  % of patients not authorized for colonoscopy using srl and 10  % of patients not authorized for colonoscopy using oc . mcnemar s test was used for nominal data , which is suitable for matched data pairs . for categorical data , the wilcoxon signed - rank test was used , a p - value less than 0.05 was considered to be statistically significant . this prospective , observational , single - center study was performed at the department of gastroenterology , deventer hospital , the netherlands . formal ethics committee review or approval was not required . between may 2012 and july 2012 , all consecutive patients referred for surveillance and diagnostic colonoscopy were de - identified and included in the analysis . two methods of identifying patients for colonoscopy were evaluated : the standardized referral letter ( srl ) and the outpatient consultation ( oc ) . standardized referral letter : the srl is a predefined list of approved indications and symptoms that warrant colonoscopy . this includes patients use of anticoagulants , a diagnosis of diabetes , with or without insulin therapy , and contagious diseases . all srls were scrutinized by an independent gastroenterologist who was instructed to use only the srl for authorization of colonoscopies . in instances where authorization for a colonoscopy was approved , the gastroenterologist determined the patient s priority for undergoing the colonsocopy : a , within one week ; b , within two weeks ; and c , first regular opportunity ( usually within 3    4 weeks ) . gastroenterologists were selected using a day - by - day rotation system , ensuring that they had no previous contact with the study patients or their medical records . outpatient consultation : every outpatient referred for colonoscopy had a standard 7.5  min face - to - face consultation with a gastroenterologist who verified the data in the patient s srl . the outpatient consultation occurred before and in addition to colonoscopy , but without a physical examination . additional information regarding patient symptoms , comorbidities , and use of medications was obtained from the patient and the electronic medical record system . when a colonoscopy was authorized , a priority level was given for that patient , and the patient met with a nurse for additional information about the procedure . when colonoscopies were not authorized for a patient , both the patient and the referring physician were informed by the gastroenterologist that the patient did not meet the criteria for the procedure . secondary outcomes were the differences in the patient s priority for colonoscopy , the number of malignancies identified , the number of advanced neoplastic lesions identified , and the number of new diagnoses of inflammatory bowel disease ( ibd ) . in addition , the completeness of the srl with respect to the patient s use of medications ( insulin and coumarins ) and their important comorbidities were recorded . important comorbidities were defined as previous abdominal surgery , cardiac disease , chronic obstructive pulmonary disease , malignancies , and coagulation disorders . the number of patients in this study ( 255 ) was determined by the following calculation ( because no data were available in the literature ) : power of 90  % ,   <  0.05 , and an estimation of 3  % of patients not authorized for colonoscopy using srl and 10  % of patients not authorized for colonoscopy using oc . mcnemar s test was used for nominal data , which is suitable for matched data pairs . for categorical data , the wilcoxon signed - rank test was used , a p - value less than 0.05 was considered to be statistically significant . secondary outcomes were the differences in the patient s priority for colonoscopy , the number of malignancies identified , the number of advanced neoplastic lesions identified , and the number of new diagnoses of inflammatory bowel disease ( ibd ) . in addition , the completeness of the srl with respect to the patient s use of medications ( insulin and coumarins ) and their important comorbidities were recorded . important comorbidities were defined as previous abdominal surgery , cardiac disease , chronic obstructive pulmonary disease , malignancies , and coagulation disorders . the number of patients in this study ( 255 ) was determined by the following calculation ( because no data were available in the literature ) : power of 90  % ,   <  0.05 , and an estimation of 3  % of patients not authorized for colonoscopy using srl and 10  % of patients not authorized for colonoscopy using oc . mcnemar s test was used for nominal data , which is suitable for matched data pairs . for categorical data , the wilcoxon signed - rank test was used , a p - value less than 0.05 was considered to be statistically significant . consecutive patients ( 255 ; 51  % men ; mean age , 61 years ; range , 19    88 years ) were included in the study . eighty - three percent of the patients were referred by a general practitioner , the others were referred by internists and surgeons . after oc , 226 patients ( 89  % ) were authorized for colonoscopy ; two patients cancelled their colonoscopies , and 224 colonoscopies were performed ( 87  % ) . in 211 ( 94  % ) patients , after srl , 239 ( 93.7  % ) consecutive patients were authorized for colonoscopy . fewer colonoscopies were authorized by oc ( 11.4  % of patients were not authorized for a colonoscopy ) than by srl ( 6.3  % of patients were not authorized for a colonoscopy ; p  =  0.02 ) . abbreviations : oc  =  7.5  min outpatient consultation ; srl  =  standard referral letter . these patients did not have a colonoscopy as shown in table  1 , seven of sixteen patients that were not authorized for colonscopy using the srl , were authorized for colonoscopy using oc , because of incomplete information on the srl ( eg . for example , one patient underwent a colonoscopy a year previously , which was sufficient reason to decline the colonoscopy using the information in the srl . using oc , however , it was noticed that the prior colonoscopy of this patient was incomplete because of fecal contamination , and the colonoscopy for this patient was then authorized . in five of the seven patients , these lesions were symptom - related and included hemorrhoids , colonic diverticular disease , and adenomatous polyps .  table 2 shows the reasons why colonoscopies were not authorized , which included symptoms related to irritable bowel syndrome ( using the rome - iii - criteria ) , recently performed colonoscopy , incorrect surveillance ( early referral or no reason for colonoscopy according to the guidelines ) , or a patient s choice for a second consultation or diagnostic tests ( upper endoscopy , sigmoidoscopy , laboratory tests , or imaging ) instead of colonoscopy . other reasons why colonoscopies were not authorized included changes in patients medications and referrals to other specialists . more colonoscopies were prioritized when gastroenterologists use the srl ( 30  % level a , 14  % level b ) than when they used the oc ( 18  % level a , 8  % level b ) . wilcoxon signed - rank test revealed a significant difference in priority assignments ( p  <  0.001 ) . colorectal cancer was detected in 5.8  % ( 13/224 ) of patients who underwent a colonoscopy . 1 shows that although fewer colonoscopies were prioritized using oc ( level a  +  b ) , more patients were diagnosed with malignancies ( 10.8  % versus 6.3  % , p  <  0.001 ) . when colonoscopies were not prioritized , malignancies were detected in 4.7  % and 3.7  % of patients using srl and oc , respectively . the accuracy of prioritization was demonstrated in that the number of patients in level a and b decreased while the number of patients with colorectal cancer in those levels increased . data from 16 ( srl ) and 29 ( oc ) subjects who were not recommended for colonsocopy . some of the patients were not recommended for more than one reason , causing the total number of reasons that patients were not recommended for colonoscopy ( srl , n  =  18 and oc , n  =  30 ) to be higher than the total number of patients who were not recommended for colonoscopy ( srl , n  =  16 and oc , n  =  29).abbreviations : srl  =  standard referral letter screening ; oc  =  7,5  min outpatient consultation ; ibd  =  inflammatory bowel disease . significance ( p  <  0.05 ) 
 the assessment of the priority of outpatient colonoscopy based on srl and oc plotted against the number of malignancies found at colonoscopy . abbreviations : srl  =  standard referral letter ; oc  =  7.5  min outpatient consultation . the most dangerous medications ( insulin , coumarins , and platelet inhibitors ) were reported in 1.6  % of the srls . medications that patients take are less relevant for colonoscopy than for other procedures , but antihypertensives , beta - blockers , and proton pump inhibitors were missing on the srls . of all patients , 63.5  % had a past medical history , which included abdominal surgery ( 35.8  % ) cardiac disease ( 15.4  % ) , copd ( 3.1  % ) , prior malignancy ( 3.7  % ) , diabetes mellitus ( 3.0  % ) , and coagulation disorder ( 0.6  % ) . in the netherlands , 191,339 colonoscopies were performed in 2009 6 . in the current study , srl , which is current practice , revealed that 16 patients ( 6.3  % ) did not require colonoscopy whereas oc revealed that 29 patients ( 11.4  % ) did not require colonoscopy . in the netherlands , 191,339 colonoscopies were performed in 2009 6 . extrapolating the results from this study to the 2009 data revealed that slr and oc would result in 12,058 and 21,812 fewer annual colonoscopies nationwide , respectively . after the introduction of the screening program for colorectal cancer ( crc ) in the netherlands , the benefits of the oc will increase , because the number of patients authorized for colonoscopies will increase by 66,000 annually in the long term 7 . reducing the number of non - screening colonoscopies by using oc reduces the workload and the financial consequences . nearly half of of those who were not recommended for colonoscopy by gastroenterologists using srl alone were authorized for colonoscopy using oc , and many of these patients had lesions that were identified during colonoscopy . thus , there are two problems with srl ; first , fewer patients were authorized to undergo colonoscopy , and , second , patients who were not originally authorized by srl were ultimately diagnosed with a lesion when the procedure was authorized after oc . this supports the importance of oc for maintaining high quality and safety for patients . relying on srl we found oc is better than srl for establishing patient priority for colonoscopy and that fewer referrals were assessed as urgent ( level a or b ) . although the number of urgent patient referrals was lower for oc , the number of diagnoses of malignancies was comparable to srl . this is supported by ramsay et al . , who reported high numbers of urgent patient referrals by general practioners and that in 92.2  % of these no malignancies were found 8 . a long patient waiting period for a colonoscopy is common for most hospitals . when the number of referrals assessed as urgent is too high , it could cause problems scheduling colonoscopies that actually are urgent . in particular , previous abdominal surgery was not reported and it is a factor known to contribute to the difficulty of a colonoscopy 9 
 10 . in 2006 , an american study reported inaccurate relevant information in 8.8  % of patient referrals in an assessment of the srl 11 . in the current study , the incomplete information on the srls was revealed upon ocs and the colonoscopies were subsequently approved . we performed a prospective study , with blinded evaluation of srl and oc to determine if patients would be recommended for colonoscopy or not . patients who were not recommended for colonoscopy by oc , did not receive colonoscopy , which is a limitation of this study . however , that determination was not the purpose of this study , and the number of patients in this group was small relative to the total number of patients . furthermore , these patients were evaluated by an experienced gastroenterologist who concurred with the decision made by oc . prioritization of colonoscopies at the deventer hospital may be relatively easy because of a short waiting period and this could have influenced the percentages of prioritized patients in our study . however , both srl and oc were evaluated using the same conditions so the differences noted remain statistically valid . patients recommended for a colonoscopy using oc met with a nurse for additional procedural information.this has a positive impact on the quality of bowel preparation , however , the impact of this meeting was not evaluated in this study . the study shows that the implementation of oc to authorize pateint referrals for colonoscopy reduced the number of authorizations for patients with improper indications . furthermore , it reduced the number of procedures that were not authorized from the srl , provided a better prioritization of patients for colonoscopies , and provided important additional information that was lacking on the srl . these findings show that oc provides important health care benefits for patients referred for colonoscopies , a reduced of risk of colonoscopies that are not justified or among patients that are too frail , and reducted costs and patient waiting times .
background and study aims : in many dutch hospitals , open access referral 
 for colonoscopy is authorized by a gastroenterologist after screening a standard 
 referral letter ( srl ) without face - to - face contact with the patient . 
 we 
 investigated the added value of a 7.5  min outpatient consultation with a 
 gastroenterologist ( oc ) , regarding the patient indications , priority for 
 colonoscopy , and the frequency of correct information about patient medications 
 and comorbidities on srls . 
 patients and methods : in a prospective , blinded , single - center study , 
 gastroenterologists assessed srls for the accuracy and priority of the 
 colonoscopy request ( srl ) . 
 these data were compared to results from the oc , and 
 primary outcomes were the number of patients who were not recommended for 
 colonoscopy and priority scheduling of colonoscopy for suspicion of cancer . 
 results : patients were analyzed using both srl and oc and , of 255 
 patients , 224 of them underwent colonoscopy . 
 colonoscopy was not recommended for 
 6.3  % and 11.4  % of patients using the srl and oc , respectively 
 ( p  =  0.02 ) . using the srl 
 , gastroenterologists did not recommend 
 colonoscopy for seven patients , but the same patients were recommended for 
 colonoscopy when oc was available . 
 this was explained because the indications on 
 the srl did not match the information obtained from oc . 
 compared to oc , more 
 colonoscopies were prioritized when the srl was used to make decisions . 
 cancer 
 was detected in 7/112 ( srl ) versus 7/65 ( oc ) of priority - scheduled patients . 
 srls did not report the use of coumarins and insulin in 1.6  % of patients or the 
 prevalence of serious comorbid conditions in 52  % of patients . 
 conclusions : a 7.5  min outpatient consultation with a gastroenterologist 
 improved the identification of indications for colonoscopy , decreased priority 
 scheduling of patients , and increased the number of patients diagnosed with 
 cancer in the prioritized group . 
 srls frequently omitted patients medications 
 and comorbidities .