|Year : 2021 | Volume
| Issue : 1 | Page : 24-28
Evaluation of quality assurance in the cytopathology laboratory of a tertiary care hospital in Eastern India
Debjani Mallick1, Sayan Kundu2, Sudipta Chakrabarti2
1 Department of Pathology, ESI PGIMSR & ESIC Medical College, Joka, Kolkata, West Bengal, India
2 Department of Pathology, ESI PGIMSR, Manicktala, Kolkata, West Bengal, India
|Date of Submission||01-Aug-2020|
|Date of Decision||18-Sep-2020|
|Date of Acceptance||02-Feb-2021|
|Date of Web Publication||02-Jul-2021|
Department of Pathology, ESI PGIMSR and ESI Hospital, Manicktala, 54 Bagmari Road, Kolkata - 700 0054, West Bengal
Source of Support: None, Conflict of Interest: None
Background: In this era of evidence-based medicine, clinical laboratories play a critical role in patient diagnosis and management.
Aims: The present study aims to study the quality assurance in the cytopathology laboratory of a tertiary care hospital in the Eastern region of India.
Materials and Methods: An observational, retrospective, and analytic study for 1 year was conducted. The sample size was 600. Simple random samples were selected including pleural fluids, ascitic fluids, cerebrospinal fluids, cervical cytology Pap smears, fine needle aspiration (FNA) cytology, and guided FNA samples.
Results: Maintenance of authentication of reports and ISO accreditation showed no deficiency, whereas report generation, dispatch, and documentation of duplicate reports showed the highest deficiency (593, 98.8%) in maintaining quality assurance. Incomplete requisition was the most common cause of registration failure (3, 42.8%), whereas samples sent in wrong vials was the most common cause of sample collection failure (3, 37.5%). The presence of artifacts was the major factor affecting smearing technique (3, 50%). Lack of compliance to standardized protocol in manual staining and mechanical factors of automated strainers affected the staining quality (3, 37.5% each). Power cut and lack of adequate UPS backup affected the productivity of equipment mostly (3, 50%). Technical issues were the major factor affecting turnaround time (3, 50%). Lack of manpower at the report dispatch counter and logistics affected report generation and dispatch (2, 33.3% each). Randomly selected reports were crosschecked with histology and prediction accuracy measures were calculated.
Conclusion: The preanalytical, analytical, and postanalytical factors have to be maintained adequately for ensuring quality assurance.
Keywords: Cytopathology, laboratory, quality assurance, quality control
|How to cite this article:|
Mallick D, Kundu S, Chakrabarti S. Evaluation of quality assurance in the cytopathology laboratory of a tertiary care hospital in Eastern India. J Curr Res Sci Med 2021;7:24-8
|How to cite this URL:|
Mallick D, Kundu S, Chakrabarti S. Evaluation of quality assurance in the cytopathology laboratory of a tertiary care hospital in Eastern India. J Curr Res Sci Med [serial online] 2021 [cited 2021 Jul 30];7:24-8. Available from: https://www.jcrsmed.org/text.asp?2021/7/1/24/320503
| Introduction|| |
Cytopathology plays an important role in the early detection of cancer and provides scope for ancillary studies to make specific diagnosis, thereby facilitating treatment protocols. While quality assurance encompasses all steps in the process, from specimen collection to transmission of report to the clinician, quality control deals with the operational techniques in daily workflow to ensure quality requirements. All the parameters of preanalytical, analytical, and postanalytical processes have to be maintained for ensuring adequate quality assurance of the tests. Preanalytical errors bear the bulk of laboratory errors comprising approximately 60%–70%. Most of the preanalytical errors comprise inadequate specimen collection, specimen transportation, and/or specimen preparation.
On the other hand, internal quality control ensures that the technical quality of products in the analytical phase meet the preestablished tolerance limits. Quality controls for the postanalytical factors have focused on critical value notification, meeting turnaround time, and crosscheck with the review of changed reports. In this background, the present study aims to study the quality assurance in cytopathology laboratory in a tertiary care hospital in the Eastern Region of India. The novelty of the study is that it takes into account of all the important and practical preanalytical, analytical, and post analytical factors affecting quality assurance of the cytopathology laboratory, which includes local availability of man (qualified and efficient technologists and cytopathologists), material (availability of stains and equipment), and money (for regular maintenance of stains, equipment, personnel, and accreditation). The objective of the study was to identify the errors in preanalytical, analytical, and postanalytical phases and also suggest recommendations based on the relevant findings to maintain a satisfactory level of quality standards in practice.
| Materials and Methods|| |
A hospital-based observational, retrospective, and analytic study was undertaken to study the quality assurance in the Department of Cytopathology of a tertiary care hospital in the Eastern Region of India. The study was conducted for 1 year. Simple random samples which were sent to the cytopathology laboratory were selscted. Inclusion criteria were all indoor and outdoor samples received in the cytopathology laboratory including pleural fluids, ascitic fluids, cerebrospinal fluids, cervical cytology Pap smears, fine needle aspiration (FNA) cytology, and guided FNA samples. Exclusion criteria were any sample without any requisition; samples with labeling errors; any fluid sample drawn more than 6 h earlier; and samples with transportation errors such as inadequately capped, showing any signs of spillage, or malhandling during transport.
Study variables included the followings:
- Number and percentage of samples accepted and rejected to maintain quality assurance
- Factors affecting quality assurance in cytopathology laboratory
- Root cause analysis of registration failure
- Root cause analysis of sample collection failure
- Root cause analysis of factors affecting smearing techniques
- Root cause analysis of failure to maintain good staining quality
- Root cause analysis of failure of productivity/maintenance of equipment
- Root cause analysis of failure of maintaining turnaround time
- Root cause analysis of factors affecting report generation and dispatch.
Sample size of the study was 600. Sample size was calculated using formula
where z= Confidence level: conventional = 95% = 1 - α; therefore, α = 0.05 and z(1-α/2) = 1.96 ; p= expected Quality assurance from previous studies = 0.95 ; d= absolute precision = 0.02.
The data were collected for all three pre analytical, analytical, and post analytical factors of standard quality assurance. The data were collected by review of records. The data were analyzed using Microsoft Excel software for estimating statistical parameters. The root cause analysis was done for the failure of quality assurance variables.
For the evaluation of internal quality control, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for fluid cytology, cervical Pap cytology, and FNA cytology were obtained after comparison with respective histopathology.
The standard turnaround time of the cytopathology laboratory was 6 h for body fluids and 48 h for cervical cytology and FNA cytology. Deviation from these values was considered as failure of maintenance of turnaround time. Standard time for report generation, dispatch, and documentation of duplicate reports was 1 h.
| Results|| |
Out of 600 samples, 552 (92%) samples were accepted and 28 (8%) samples were rejected to maintain quality assurance. Maintenance of authentication of reports and maintenance of ISO accreditation showed no deficiency, whereas report generation, dispatch, and documentation of duplicate reports showed the highest deficiency (593, 98.8%) in maintaining quality assurance. Incomplete requisition was the most common cause of registration failure (3, 42.8%), whereas samples sent in wrong vials was the most common cause of sample collection failure (3, 37.5%). The presence of artifacts (contaminants of vials, drying, and excess blood) was the major factor affecting smearing technique (3, 50%). Lack of compliance to standardized protocol in manual staining as well as mechanical factors of automated strainers affected the staining quality (3, 37.5% each). Power cut and lack of adequate UPS backup were major factors which affected the productivity of equipments (3, 50%). Technical issues (equipment out of order) were the major factor affecting turnaround time (3, 50%). Lack of manpower at the report dispatch counter and availability of logistics majorly affected report generation and dispatch (2, 33.3% each) [Table 1], [Table 2], [Table 3] and [Figure 1].
|Table 1: Factors affecting quality assurance in cytopathology laboratory|
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|Table 2: Root cause analysis of failure to maintain good staining quality|
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Randomly selected 150 samples (50 fluids, 50 cervical cytology, and 50 FNAC) were crosschecked with respective histopathology as internal quality control, and the following prediction accuracy measures were calculated. Simple randomization technique was adopted for this purpose. For fluid cytology, sensitivity was 72%, specificity 85%, PPV 58%, and NPV 86% (95% CI). For cervical Pap smear, sensitivity was 87%, specificity 78%, PPV 85%, and NPV 80% (95% Cl). For FNAC, sensitivity was 98%, specificity 92%, PPV 93%, and NPV 97% (95% Cl) [Table 4] and [Figure 2].
|Figure 2: (a) Pleural fluid cytology showing atypical cells with high nuclear cytoplasmic ratio and hyperchromasia in a case of malignant pleural effusion (Pap, ×400). (b) Cell block histology of the same fluid confirms the presence of atypical cells (H and E, ×100). (c) Immunohistochemistry of the same cell block shows cytoplasmic positivity of CK20 in the malignant cell clusters (CK 20, ×100). (d) Cervical cytology smear in a case of low-grade squamous intraepithelial lesion (PAP, ×400)|
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| Discussion|| |
In the present study, quality assurance variables were studied in the cytopathology laboratory with respect to the pre analytical, analytical, and post analytical factors. Out of 600 samples tested, the rejection rate was 8% to maintain quality assurance of the test results.
In the study of Gupta et al., there was 7% samples rejection and the issues of the request form and sample comprised nearly 50% rejections. In the present study, rejection rate was 8% and pre analytical errors contributed major factor for rejection of samples. In the present study, incomplete requisition forms and incorrect identification details and numbering on the sample comprised 42.8% and 28.6% of registration failure.
Mehrotra et al. found that the main reason of rejection was due to inadequacy of specimen collection. The present study showed sample sent in wrong vials (37.5%) and inadequate volume (25%) attributed majorly to sample collection failure.
Interpretation of cytology samples is dependent on sample processing, smearing, and staining. Gill opined that for nongynecologic specimens, inadequate sampling, ﬁxation, and staining contribute to false-negative results. For both gynecologic and nongynecologic specimens, the cytotechnical factors which cause false-negative results are as follows: first, low cellularity may be due to limitations in the specimen character or an pseudolimitation due to inadequate preparation; second, air-drying, poor ﬁxation, understaining, and overstaining minimize contrast differences between normal and atypical cells, thus interfering with the interpretation. The present study found presence of artifacts like contaminants of vials, drying or excess blood (50%), and lack of compliance and adaptability to newer techniques like cytospin (33.3%) were the major determinants affecting the smearing quality. Whereas, both lack of compliance to standardized protocol in manual staining (37.5%) and mechanical factors of automated strainers and cover slippers (37.5%) affected the maintenance of good staining quality in the present study.
Kumar and Jani opined that improvisation of automated devices enhances the sensitivity of Pap smear. They suggested the following areas of automation: sample preparation, screening process devices, imaging system to identify abnormal cells, automatic staining and cover slipping, data storage, and retrieval systems. The goals of automating the cytology laboratory are improving the accuracy of, shortening the turnaround time, and obtaining a good quality representative slide. The productivity of the automated systems may fall short due to many issues such as lack of adequate UPS backup (50%) and lack of regular preventive maintenance (16.7%) as seen in the present study.
As per Wankar, the reasons for the delay in turnaround time in laboratory were due to delay in transportation time, delay in collection counter, instrumentation failure, and abnormal reports needing verification. Similarly, in the present study, delay in turnaround time was primarily due to technical factors such as equipment out of order (50%) and shortage of supply of materials (33.33%).
Plebani enlisted the common post analytical errors, which are incorrect validation of data, erroneous data entry, transcription error, and critical values reporting failure. In the present study, lack of manpower at report dispatch counter (33.3%) and lack of logistics (33.3%) were the major critical areas affecting report generation and dispatch contributing to post analytical quality management. Jones et al. found that extended turnaround times were associated with seeking clinical information from the physician's office, using trainee technology students in sample preparation, residents, or fellows in the evaluation, whether or not providing service on the weekend. In the present study, technical factors (equipment out of order) and shortage of supply of materials such as stains and slides comprised major factors (50% and 33.3%, respectively) affecting turnaround time.
Other factors affecting quality assurance such as adequate authentication of reports (100%) and maintenance of ISO accreditation (100%) were studied and found satisfactory; hence, root cause analysis was not further required. Accreditation is relevant for measuring progress in professional competency and also for improving standards of laboratory practice. Accreditation standards are regarded as optimal and achievable. Hence, implementing accreditation is critical for good laboratory practice. According to ISO: 9001-2015, an internationally based certification program, all the important documentation should be assembled in a quality manual. Quality assurance procedures guarantee that the procedure protocols will be adequately implemented. For this reason, it is assumed that ISO accreditation supports good practices for the quality assurance process. Hence, in the present study, one of the objectives was studying whether the ISO accreditation process was followed in the cytopathology laboratory and found compliant with their standards.
Regarding confirmation of accuracy of analytical part, histopathological confirmation is an acceptable reference standard. In the present study, the cytology reports were randomly correlated with histology reports and the results were statistically analyzed.
For pleural fluid, the sensitivity, specificity, and NPV was 70%, 100%, and 37% (CI: 27–54), respectively, in the study of Khan et al.
As part of internal quality control, the fluid cytology was compared with cell block histology, and the findings were sensitivity 72%, specificity 85%, PPV 58%, and NPV 86%.
For cervical Pap smear study, sensitivity, specificity, PPV, and NPV were 81.8%, 78.2%, 64.2%, and 90%, respectively, in the study of Singhal et al. In the present study, the values were as follows: for sensitivity, 87%; specificity, 78%; PPV, 85%; and NPV, 80% (95% Cl).
Gillani et al. found that the values for sensitivity for intraoral FNAC: 100, for specificity: 89% PPV: 97% and NPV: 100%. The present study showed sensitivity 98%, specificity 92%, PPV 93%, and NPV 97% for FNAC (95% Cl).
| Conclusion|| |
Patient management is dependent on the laboratory results. Thus, there is critical responsibility of ensuring the reliability of its reports generated. The present study recommends the following to maintain quality assurance: complete requisition forms, complete patient identification on the vials and slides, samples to be collected in proper vials with adequate volume, reduction of the artifacts and use of newer technologies for smearing and staining, strict adherence to staining standard operating procedures and maintenance of the equipment will reduce the preanalytical errors. For the analytical errors, frequent crosschecking with histology samples will be helpful. For post analytical errors, to maintain turnaround time and report dispatch, maintaining the equipment, logistics and adequate manpower mobilization is suggested.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]