Random Blinded Rechecking (RBRC) is the process of re-reading a statistically valid sample of routine slides from a designated microscopy centre (DMC) based on lot quality assurance strategy (LQAS) in a blinded manner to assess the laboratory performance.
RBRC Process
Annual slide sample and the monthly sample for Random Blinded Rechecking (RBRC) is determined by the District TB Officer (DTO), assisted by the Intermediate Reference Laboratory (IRL), Statistical Assistant (SA) or Data Entry Operator (DEO) based on Lot Quality Assurance Sampling (LQAS) method.
Under the LQAS method, sample size depends on 3 components:
Process of RBRC (Figure 1)
Random Blinded Rechecking (RBRC) is an External Quality Assurance (EQA) method that provides reliable assurance that a district has an efficient Acid-fast Bacillus (AFB) microscopy laboratory network to support National TB Elimination Programme (NTEP) (Figure).
Blinded rechecking is a process of re-reading a statistically valid sample of slides from a laboratory to assess whether that laboratory has an acceptable level of performance.
Documentation of any significant problems (technical, operational, others) and feedback for corrective action during On-site Evaluation (OSE) is necessary to formulate plans with the District TB Officer (DTO), Senior TB Laboratory Supervisor (STLS), Medical Officer (MO), Intermediate Reference Laboratory (IRL), National Reference Laboratory (NRL) and Laboratory Technician (LT) to improve the quality of smear microscopy.
Checklists for OSE
A field visit is an ideal way to obtain a realistic assessment of the conditions and skills practiced in the laboratory. Under National TB Elimination Programme (NTEP), On-site Evaluation (OSE) of Intermediate Reference Laboratories (IRLs) and District TB Centres (DTCs)/ Designated Microscopy Centres (DMCs) is therefore an essential component of a meaningful Quality Assurance (QA) programme.
Panel testing is a method of External Quality Assurance (EQA) that is used to determine the adequacy of a laboratory technician to perform Acid-fast Bacillus (AFB) smear microscopy. This method evaluates individual performance in staining and reading and not the other laboratory activities.
Quality Assurance (QA) is a systematic process used to determine the quality standards of TB laboratories.
Poor quality diagnosis may results in failure to diagnose TB or unnecessary treatment of non-TB case. Thus an effective QA mechanism is important for reliability of laboratory diagnosis.
QA in National Tuberculosis Elimination Programme (NTEP) consists of:
The administrative measures at a health care facility play an important role in preventing the spread of TB in health care settings. It includes Administrative controls for outpatient and inpatient settings
Administrative measures at Outpatient(OPD) settings
1. Screen for respiratory symptoms as early as possible upon patient’s arrival at the health care facility thereby reducing the overall stay of such patients in the healthcare facility
Ventilation is defined as the supply/ distribution/ exchange or removal of air from spaces by mechanical or natural means.
Mycobacterium tuberculosis is transmitted in airborne particles called droplet nuclei that are expelled when a person with pulmonary TB coughs, sneezes, shouts, or sings. People nearby may breathe in these bacteria and become infected.
Airborne infection control is essential to prevent the spread of TB within a health facility and other settings.
Hierarchy of Controls to Reduce Risk of Transmission of TB (see the Figure)