A multi-center research on the establishment and validation of autoverification rules for blood analysis / 中华检验医学杂志

Objective@#To establish a set of rules for autoverification of blood analysis, in order to provide a way to validate autoverification rules for different analytical systems, which can ensure the accuracy of test results as well as shorten turnaround time (TAT) of test reports.@*Methods@#A total of 34 629 EDTA-K2 anticoagulated blood samples were collected from multicenter cooperative units including the First Hospital of Jinlin University during January 2017 to November 2017. These samples included: 3 478 cases in Autoverification Establishment Group, including 288 cases for Delta check rules; 5 362 cases in Autoverification Validation Group, including 2 494 cases for Delta check; 25 789 cases in Clinical Application Trial Group. All these samples were analyzed for blood routine tests using Sysmex XN series automatic blood analyzers.Blood smears, staining and microscopic examination were done for each sample; then the clinical information, instrument parameters, test results and microscopic results were summarized; screening and determination of autoverification conditions including parameters and cutoff values were done using statistical analysis. The autoverification rules were input into Sysmex Laboman software and undergone stage Ⅰ validation using simulated data, and stage Ⅱ validation for post-analytical samples successively. True negative, false negative, true positive, false positive, autoverification pass rate and passing accuracy were calculated. Autoverification rules were applied to autoverification blood routine results and missed detection rates were validated, and also data of autoverification pass rate and TAT were obtained.@*Results@#(1)The selected autoverification conditions and cutoff values included 43 rules involving WBC, RBC, PLT, Delta check and abnormal characteristics. (2)Validation of 3 190 cases in Autoverification Establishment Group showed the false negative rate was 1.94%(62/3 190)(P<0.001), autoverification pass rate was 76.74%, passing accuracy was 97.47%; Validation of 2 868 cases in Autoverification Validation Group, the false negative rate was 3.38%(97/2 868)(P=0.002), autoverification pass rate was 42.26%, passing accuracy was 92.00%; Validation of Delta check on 288 cases in Autoverification Establishment Group and 2 494 cases in Autoverification Validation Group showed the false negative rates were respectively 1.39% and 2.61%(P<0.001). (3)Three hospitals adopted these rules of autoverification for 25 789 blood routine samples, and found that the average TAT of blood routine test reports were shortened by 24min, 32min and 7min respectively, the rate of samples reported within 30min were elevated by 33%, 53% and 7%. The autoverification pass rates were 72%-74%.@*Conclusions@#The application of this set of 43 autoverification rules in blood sample analysis can ensure test quality while shortenTAT and improve work efficiency. It is worth pointing out that for the same analytical systems in this research, validation is necessary before application of this set of rules, and periodic validation is required during application to make necessary adjustment; for different analytical systems, as this research provide a way to establish autoverification rules for blood routine tests.Clinical labs may establish their own suitable autoverification rules on the basis of technological parameters. (Chin J Lab Med, 2018, 41: 601-607)

Changes of meibomian gland function and the stability of tear film after long-term wearing orthokeratolog / 中华实验眼科杂志

Objective This study was to observe the meibomian gland scores,the miss rate of meibomian,break-up time of tear film (BUT) changes after long-term wearing orthokeratolog,and to evaluate orthokeratolog impact on meibomian gland function and the stability of the tear film.Methods A prospective case-controlled study was performed.Fifty patients 98 eyes with myopia were enrolled.According to the myopia correction mode,the patients were divided into control group (24 cases) and experimental group (overnight orthokeratolog treatment) group (26 cases).All subjects were underwent the examinations sequentially as follows:evaluation of ocular surface disease symptoms using the Ocular Surface Disease Index (OSDI),lid margin and ocular surface examination by slit lamp microscrope,infrared meibomian photography and BUT.All measurements were repeated at 3 months,6 months,24-months follow-up visit.All patients signed informed consent before examination.Results After wearing orthok-contact lens for 24 months,the meibomian gland score was 4.54±1.10 and 2.29±0.75 in the experimental group and control group,respectively,the difference was statistically significant (P＜0.05).The BUT was (6.35 ± 1.52) s 24 months after wearing orthokeratolog,which was less than (9.38 ± 1.88) s in the control group,the difference was statistically significant (P＜ 0.05).The miss rate of meibomian gland was 24.39 ± 5.54 and 22.81 ± 5.23 in the experimental group and control group,respectively.There was no statistically significant difference among the the miss rate of meibomian gland between groups and within groups (all at P＞0.05).Conclusions Long-term wearing orthokeratolog has negetive effects on meibomian gland function and the stability of the tear film.

Miss rate of colorectal neoplastic polyps and risk factors for missed polyps in consecutive colonoscopies

BACKGROUND/AIMS: Colonoscopic polypectomy is the best diagnostic and therapeutic tool to detect and prevent colorectal neoplasms. However, previous studies have reported that 17% to 28% of colorectal polyps are missed during colonoscopy. We investigated the miss rate of neoplastic polyps and the factors associated with missed polyps from quality-adjusted consecutive colonoscopies. METHODS: We reviewed the medical records of patients who were found to have colorectal polyps at a medical examination center of the Kangbuk Samsung Hospital between March 2012 and February 2013. Patients who were referred to a single tertiary academic medical center and underwent colonoscopic polypectomy on the same day were enrolled in our study. The odds ratios (ORs) associated with polyp-related and patient-related factors were evaluated using logistic regression analyses. RESULTS: A total of 463 patients and 1,294 neoplastic polyps were analyzed. The miss rates for adenomas, advanced adenomas, and carcinomas were 24.1% (312/1,294), 1.2% (15/1,294), and 0% (0/1,294), respectively. Flat/sessile-shaped adenomas (adjusted OR, 3.62; 95% confidence interval [CI], 2.40–5.46) and smaller adenomas (adjusted OR, 5.63; 95% CI, 2.84– 11.15 for ≤5 mm; adjusted OR, 3.18; 95% CI, 1.60–6.30 for 6–9 mm, respectively) were more frequently missed than pedunculated/sub-pedunculated adenomas and larger adenomas. In patients with 2 or more polyps compared with only one detected (adjusted OR, 2.37; 95% CI, 1.55–3.61 for 2–4 polyps; adjusted OR, 11.52; 95% CI, 4.61–28.79 for ≥5 polyps, respectively) during the first endoscopy, the risk of missing an additional polyp was significantly higher. CONCLUSIONS: One-quarter of neoplastic polyps was missed during colonoscopy. We encourage endoscopists to detect smaller and flat or sessile polyps by using the optimal withdrawal technique.

Analysis of relative risk factors influencing miss rates of colorectal adenomas during colonoscopy / 中华消化内镜杂志

Objective To analyze the miss rates of colorectal adenomas during colonoscopy as well as risk factors influencing the adenoma miss rates and to take corresponding measures. Methods A total of 432 patients who underwent index and follow-up colonoscopy in 18 months were randomized and investigated. The results of two colonoscopies were compared and the missed adenomas were defined as the adenomas de-tected only during the second colonoscopy. Miss rates were calculated according to patient-based methods. Chi-square test was used to analyze the relative factors influencing the adenoma miss rate of per-patient. Then the meaningful factors were chosen into the logistic regression model for multiple factors analysis. Results Of 432 patients,116(26. 9%)had missed adenomas on first colonoscopy. Single factor analysis found that the size of adenoma( χ2 = 89. 686,P = 0. 000),the shape of adenoma( χ2 = 68. 488,P = 0. 000),the location of adenoma(χ2 = 77. 055,P = 0. 000)and adenoma tissue types(χ2 = 417. 000,P = 0. 000)were the risk factors for miss rates of colorectal adenomas. Number of polyps(χ2 = 8. 450,P= 0. 038),the organi-zation type of polyp(χ2 = 10. 718,P= 0. 013)and proficiency of colonoscopists(χ2 = 56. 069,P= 0. 000), the quality of bowel preparation(χ2 = 39. 195,P = 0. 000),insertion time(χ2 = 13. 133,P = 0. 001)were also the risk factors for miss rates of colorectal adenomas. Logistic regression analysis showed that the bigger the adenoma size,the less missed adenomas(OR= 0. 341,95%CI:0. 173-0. 671). Also,the longer insertion time took,the lower the adenoma miss rate(OR = 0. 987,95% CI:0. 981-0. 994). Per-patient miss rates were lower for high-risk adenomas compared with low-risk adenomas(OR = 0. 324,95%CI:0. 154-0. 680). Adenomas happening in multiple parts of bowel easily leads to missing(OR= 3. 791,95%CI:1. 505-9. 546). Conclusion The missed diagnosis of adenomas is not only significantly associated with features of missed adenomas,but also with skills of colonoscopists,insertion time,and bowel preparation. The key is high-quality index colonoscopy to avoid adenomas missing.

Factors Influencing the Miss Rate of Polyps in a Tandem Colonoscopy Study / 대한소화기학회지

BACKGROUND/AIMS: The miss rate of colon polyps and its related factors have not been clearly identified yet. This study aims to review the miss rate of polyps both on the patient-level and on the polyp-level and to analyze the factors affecting the miss rate such as those related to the endoscopist, procedure, patient, and polyp. METHODS: From August 2011 to August 2013, patients who underwent elective second colonoscopy for resection of polyps, the sizes of which were not small enough to be resected by biopsy forceps alone at first colonoscopy, were enrolled retrospectively. RESULTS: The miss rate on the patient-level was 59.2% (234/395) and on the polyp-level was 27.9% (578/2,068). There was no significant difference in the miss rate depending on the experience of the endoscopists or characteristics of the patients. In terms of the procedure, the miss rate was higher when the colonoscopy was performed in the afternoon (OR 1.632, p=0.046). It was found that the miss rate of polyps increased when the polyps were small (OR 4.595, p<0.001 in <5 mm/OR 3.447, p<0.001 in 5-10 mm), flat or sessile (OR 2.406, p<0.001 in flat/OR 1.768, p=0.002 in sessile), and located in the left colon (OR 1.391, p=0.007). CONCLUSIONS: The experience of endoscopists did not have influence on the accuracy of polyp detection. However, the fatigue of endoscopists in the afternoon is considered to render polyp detection less accurate. Also, the large curves and folds of the sigmoid colon are regarded as a reason for the higher miss rate of polyps in the left colon.

Importance of Early Follow-up Colonoscopy in Patients at High Risk for Colorectal Polyps

PURPOSE: Minimizing the polyp miss rate during colonoscopy is important for patients at high risk for colorectal polyps. We investigated the polyp miss rate and the factors associated with it in high-risk patients. METHODS: The medical records of 163 patients who underwent follow-up colonoscopy between January 2001 and April 2010, which was within 9 months after a polypectomy, because the index colonoscopy had shown multiple (more than 3) adenomas or advanced adenoma were retrospectively reviewed. Miss rates were calculated for all polyps, for neoplastic polyps and for advanced adenomas. Factors associated with the miss rates in these patients, such as the location, shape and size of the polyp, were analyzed. RESULTS: The miss rates for polyps, adenomas, adenomas or =5 mm and advanced adenomas were 32.6%, 20.9%, 17.7%, 3.2%, and 0.9%, respectively. No carcinoma, except for one small carcinoid tumor, was missed. Flat shape and small size (<5 mm) were significantly associated with adenoma miss rate. The miss rate was significantly higher for flat-type advanced adenomas than for protruded-type advanced adenomas (27.7% vs 4.1%). CONCLUSION: The polyp miss rate in patients at high risk for colorectal polyps was higher than expected. Efforts are needed to reduce miss rates and improve the quality of colonoscopy. Also, early follow-up colonoscopy is mandatory, especially in patients at high risk.

The Miss Rate for Colorectal Adenoma Determined by Quality-Adjusted, Back-to-Back Colonoscopies

BACKGROUND/AIMS: Colonoscopy is considered to be the gold standard for detecting adenomatous polyps. Polyps are missed during colonoscopic examination at a rate that varies from 6% to 27%. The adenoma miss rate affects colonoscopic surveillance intervals and procedural quality. We aimed to assess the adenoma miss rate and the variables affecting the rate using same-day, quality-adjusted, back-to-back colonoscopies. METHODS: This prospective study was performed at a single institution and included 149 patients. Two consecutive same-day colonoscopies were performed by two experienced endoscopists. The adenoma miss rates and variables affecting the missed adenomas, including polyp characteristics and procedure times, were evaluated. RESULTS: The miss rates of polyps, adenomas, and advanced adenomas were 16.8%, 17%, and 5.4%, respectively. The smaller polyps and increased number of polyps detected during the first colonoscopy were more likely to be missed. A longer insertion time during the colonoscopy was correlated with an increased adenoma detection rate. CONCLUSIONS: There was a significant miss rate in the detection of colonic adenomas even in quality-adjusted, back-to-back colonoscopies. The adenoma miss rate can be reduced with a sufficient observation time during colonoscopic insertion. The development of specific technological methods to reduce the adenoma miss rate is necessary.

The Effect of the Bowel Preparation Status on the Risk of Missing Polyp and Adenoma during Screening Colonoscopy: A Tandem Colonoscopic Study

BACKGROUND/AIMS: Although a small amount of fecal material can obscure significant colorectal lesions, it has not been well documented whether bowel preparation status affects the missing risk of colorectal polyps and adenomas during a colonoscopy. METHODS: We prospectively enrolled patients with one to nine colorectal polyps and at least one adenoma of >5 mm in size at the screening colonoscopy. Tandem colonoscopy with polypectomy was carried out within 3 months. RESULTS: A total of 277 patients with 942 polyps and 714 adenomas completed index and tandem examinations. At the index colonoscopy, 187 polyps (19.9%) and 127 adenomas (17.8%) were missed. The per-patient miss rate of polyps and adenomas increased significantly as the bowel cleansing rate declined from excellent to poor/inadequate on the Aronchick scale (polyps, p=0.024; adenomas, p=0.040). The patients with poor/inadequate bowel preparation were independently associated with an increased risk of having missed polyps (odds ratio [OR], 3.21; 95% confidence interval [CI], 1.13 to 9.15) or missed adenomas (OR, 3.04; 95% CI, 1.04 to 8.88) compared to the patients with excellent bowel preparation. CONCLUSIONS: The risk of missing polyps and adenomas during screening colonoscopy is significantly affected by bowel preparation status. It seems appropriate to shorten the colonoscopy follow-up interval for patients with suboptimal bowel preparation.

Narrow Band Imaging and White Light Colonoscopy for Detection of Polyps / 대한소화기내시경학회지

BACKGROUND/AIMS: Narrow band imaging (NBI) is a new technique that is expected to improve the detection rate of colorectal polyps, but results have been inconsistent. The aim of this study was to compare the polyp miss rate and the characteristics of missed colorectal polyps using white light (WL) and NBI. METHODS: 62 patients were randomized into two groups. In the first group (NBI first, NBIF), a colonoscopic examination of each segment (cecum-ascending, transverse, descending, and rectosigmoid colons) was performed first with NBI followed by a re-examination of the same segment using WL. An opposite sequence was applied for the other group (white light first, WLF). RESULTS: 67 polyps were found in the first examination, and 31 polyps were found on the re-examination, resulting in a polyp miss rate of 31.6%. The polyp miss rate was 39% for WLF and 23% for NBIF (p>0.05). Seventy-four small polyps (<5 mm) were found, and miss rates for NBIF and WLF were 20% and 46%, respectively (p=0.01). The polyp miss rate at the rectosigmoid was 11% for NBIF and 54% for WLF (p=0.01). CONCLUSIONS: The polyp miss rate was not significantly different between NBI or WL when a colonoscopy was performed. NBI resulted in a lower polyp miss rate for small (<5 mm) and rectosigmoid polyps than WL.

Rate and risk factors of missed diagnosis of colorectal adenoma with colonoscopy / 中华消化内镜杂志

Objective To investigate the miss rate of adenoma with colonoscopy and assess the features and risk factors for missed diagnosis.Methods Patients with colorectal adenoma received a second colonoscopy within 120 days after adenoma was detected and removed on the initial colonoscopy.The findings of two colonoscopies were reviewed and analyzed.The features of adenoma (including size, location, shape, number and pathology) , clinical characteristics of patients (including age, sex, reasons of colonoscopy, history of diverticular disease, history of abdominal or pelvic surgery and colonoscopy with sedation) and endoscopists were recorded.Miss rate and features of different types of missed adenoma were analyzed.We also assessed the effects of adenoma features, patients' characteristics and endoscopists on missed diagnosis of adenoma.Results Adenoma missed diagnosis was found in 271 patients out of 809 recruited subjects (33% ).A total of 425 adenomas were missed out of 2134 (20% ) adenomas detected by repeated colonoscopy.A large diameter was associated with a decrease in the miss rate for adenoma (P < 0.01).Conversely , sessile or flat shape (P < 0.01) , locations at sigmoid, hepatic flexure, cecum and ascending colonic ( P < 0.05) were significantly associated with a higher miss rate of adenoma, as was the number of adenomas (P <0.01).A higher adenoma missed diagnosis rate was observed in beginner colonoscopists, as compared with experienced ones (P < 0.01).Conclusion A marked miss rate of adenoma exists on colonoscopy, which is significantly associated with the size, shape, location and number of adenomas and endoscopists.

Endoscopic and Histopathologic Predictors of Recurrence of Colorectal Adenoma on Lowering the Miss Rate

BACKGROUND/AIMS: Although colorectal adenoma is reported to recur frequently, this may result from missing it at baseline. However, few studies of recurrence have considered the miss rate. This study evaluated the recurrence rate prospectively and clinical predictors of recurrence in colorectal adenoma after lowering the miss rate. METHODS: The study population comprised 128 patients who underwent baseline colonoscopy with resection of colorectal adenomas. Re-examination to lower the miss rate was performed within 2 months. Follow-up colonoscopy to detect recurrence was done more than 1 year after removal. RESULTS: The mean follow-up period was 35.1 months (range, 12 to 84 months). Thirty patients had a recurrent adenoma, for a recurrence rate of 23.4%. Older patients (over 60 years) had a two-fold greater risk of recurrence than younger patients (hazard ratio, 2.39; 95% confidence interval [CI], 1.16-4.90). Patients with three or four adenomas at baseline colonoscopy had a two-fold greater risk than those with one adenoma (hazard ratio, 2.44; 95% CI, 1.11-5.35). Patients with advanced adenoma had a two-fold greater risk than those with no advanced adenoma (hazard ratio, 2.88; 95% CI, 1.40-5.95). In multivariate analysis, only the presence of three or four adenomas independently predicted the recurrence of adenoma (hazard ratio, 3.19; 95% CI, 1.04-9.79). CONCLUSIONS: The recurrence rate of colorectal adenoma corrected by lowering the miss rate was lower than reported rates. The presence of multiple adenomas on initial colonoscopy was an important predictor of recurrence.

Colonoscopic Miss-rate of Colorectal Polyp and Adenoma / 대한소화기내시경학회지

BACKGROUND/AIMS: While colonoscopy is the gold standard diagnostic test for the detection of colorectal polyps (especially adenomas), it is also an imperfect method. We prospectively estimated the colonoscopic miss-rate of colorectal polyp and adenoma. METHODS: We performed polypectomies in 603 out of 2,006 patients over age of 40 who underwent their first time colonoscopy between September 1999 and June 2001. A follow-up colonoscopy was performed within 60 days in 235 (53.4%) among 440 enrolled patients. RESULTS: Seventy-three (31.0%) of 235 patients with polyps on initial colonoscopy were missed polyps and 37 (23.2%) of 159 patients with adenomas on initial colonoscopy were missed adenomas. As the number of polyps on the initial examination increased, the miss-rate increased significantly (p=0.01). The most frequent size of missed polyp was 3~4 mm (55.5%, p=0.00) and the most frequent location was sigmoid colon (27.3%, p=0.00). CONCLUSION: It may be a fallacy to declare that all colorectal polyps are removed just after one session of colonoscopy. Examiners should make every effort to reduce the miss-rate of colorectal polyps during colonoscopy.