Tools, Technologies and Training for Healthcare Laboratories

Basic QC Practices

QC - The Records

Tricia Barry MT(ASCP) gives us another valuable article on the basics of quality control, explaining the who, what, when and how of recording your QC history -- plus the why we need to do it. It turns out your records are important - they provide a voice for the method. If you listen closely, you'll understand why things are out-of-control sometimes.

Note: An updated version of this lesson is now available in Basic QC Practices, 2nd Edition.

The words "documentation" and "records" often give people a negative feeling, so let's get rid of that right away. Let's think about "history" rather than documentation. We know we can study history and learn from the past, from the successes of others, and also their failures. Many times the failures are even more useful than the successes because they can help us understand what went wrong, the nature of the problem, and what the causes might have been. Likewise, we can learn from the history of a laboratory testing process. It can help us solve today's problems and prevent tomorrow's problems!

The history is kept in various records. I like to think of these records as "voices" of the process - each one telling us something about what is or has been going on. The voices tell us about the performance when a method was first evaluated, when daily quality control and proficiency testing samples were tested, the frequency and type of problems encountered under routine conditions, and what changes were needed to correct problems or improve operation. We may not need to look at all the records every time a problem needs to be solved. However, listening to several "voices" simultaneously allows us to see a process in context and, thereby, make better decisions about waht to do to improve. You know the old saying "There are always [at least] two sides to every story." Let's listen to all the "voices" of the process.

Keeping the History - The Why

The history of an analytical process should include all the information (generated in the normal operation of that process) necessary to describe performance and to identify factors that affect performance. This information is recorded on paper or in electronic format, usually in chronological order, thereby giving a "history" of the process. This history provides a core of facts about the process and its performance under both stable and unstable conditions, including evidence of quality -- or the lack thereof. It can be used to describe past performance and current performance, to aid immediate troubleshooting and corrective action, and to guide future improvements.

Recording the History - The What

The minimum information that should be recorded can be identified from the regulatory and accreditation requirements. This usually includes:

  • A complete description of the process, i.e., the method procedure;
    Initial evaluation data to document method performance, e.g., working range, precision, accuracy, analytical sensitivity, analytical specificity, reference range;
  • Daily information about routine operation, which includes the analyst, observed control values, decisions made about the control values, identification of any problems, documentation of any corrective actions, and evidence of supervisory review.

You should also consider what additional information is necessary based on good laboratory practice and the needs for maintaining and improving the performance of the process. For example, to document the actual performance of a testing process, the quality control records should include :

  • All individual data values;
  • Summary statistics - monthly (or appropriate period) and cumulative;
  • QC problems and decisions (accept, reject, overrides);
  • Troubleshooting activities;
  • Corrective actions and followups;
  • Proficiency testing results.

Additional information is needed to document important variables that might affect the stability of the process, such as:

  • Preventive maintenance - scheduled and unscheduled;
  • Reason for maintenance, what was done, by whom;
  • Frequency and length of downtime;
  • Signs of instrument deterioration;
  • Calibration, calibration verification - scheduled and unscheduled;
  • Lot numbers and expiration dates of calibrators, date of calibration or verification, reason for the calibration or verificaiton, by whom, results;
  • Reagent changes - planned and unplanned;
  • Lot numbers and expiration dates, what was changed, why, by whom;
  • Instrument function checks (temperatures, alignments, gating, etc.).

Appropriate SQC must be performed after some of the above activities and these QC results must be included with these records or at least traceable to them (e.g., coded comments in a QC database). For example, if a calibration is performed, the QC materials must be assayed immediately after to be sure the process is in control before proceeding with patient testing.

Recording the History - The How

The format for recording information must permit convenient, timely review by being clear, complete, and well organized. The record must be current and contain all the relevent information. This means recording the information as the events happen and as corrective actions are taken in order to support decisions using most current information on process performance. Permanent paper or electronic records are necessary, rather than verbal communication of current events. A well thought out system is needed to collect, organize, and store all this data and information. Note that regulatory and accreditation guidelines often specify that QC records, reagent changes, calibrations, etc., must be available for at least a two-year period, and that all maintenance records must be kept for the lifetime of the instrument system and transferred with the instrument.

JCAHO provides examples of a wide variety of forms that may be useful starting points for developing your record keeping system [1].

Recording the History - The Who

A supervisor, lead analyst, or QC specialist is often responsible for the organization of the initial method evaluation study, but many other analysts may participate in the studies and be involved in collecting the method performance data. While it is common practice today to have a manufacturer's technical specialist perform in-laboratory studies when major systems are being set up, the laboratory needs to maintain it's responsibility for such studies, specify what studies are to be done and how much data needs to be collected, establish the criteria for acceptance, and make an independent assessment of the data and independent judgments on the acceptability of method performance. A formal report of the method evaluation study should be filed and available for reference in the future.

Everyone who operates a method has the responsibility for recording any changes they make to the testing process, control results they obtain during operation, decisions on reporting or not reporting patient test results, and corrective actions made. Collection of this diverse information from many different analysts requires an effective record keeping system.

It is also important to assign system responsibility to a specific analyst, QC specialist, or supervisor who reviews the daily QC, reviews proficiency testing results, follows up on problems, reviews the monthly QC statistics, updates the cumulative QC statistics, identifies chronic and long-term problems with the system, and recommends additional studies, changes, or improvements. This individual may also have responsibilities for reviewing method evaluation studies, selecting appropriate QC procedures, and periodically reassessing or validating the QC design.

Learning from History

You have to study history to learn from the past. This means reviewing QC records daily, weekly, and monthly, as well as performing periodic quality audits. These studies will aid troubleshooting and help correlate daily performance data with information from method evaluation experiments, proficiency testing surveys, and patient test results. Findings should lead to better preventive maintenance, improved training of analysts, and redesign of troublesome steps in the testing process.

It's difficult for analysts to assimilate all this information and have it available for immediate use unless they spend a lot of time working with it. We have found it effective to have Quality Specialists who spend at least half their time focusing on QC issues to keep on top of everything - from method evaluation, routine QC, proficiency testing, QC planning, and quality improvement. There are certain people who are natural "historians", intrigued by studying the past, skilled at sorting and organizing data and information, oriented to quantitative analysis and interpretation, perceptive at identifying the special causes of events, challenged by understanding the lessons told by the data and information, and enthused by telling and documenting the stories. Those talents make them well-suited for special responsibilities for analytical quality management.

References:

  1. How to Meet the Most Frequently Cited Laboratory Standards. Oakbrook Terrace, IL: Joint Commission on Accreditation of Healthcare Organizations, 1996.