QUALITY ASSURANCE FOR LUNG FUNCTION LABORATORIES

Transcription

1 ARTP Working Groups on Standards of Care and Recommendations for Lung Function Departments (2006) QUALITY ASSURANCE FOR LUNG FUNCTION LABORATORIES CONTENTS 1. ARTP Working Groups 2. Scope Of This Document 3. Introduction 4. Staffing 4.1 Training 5. Equipment 5.1 Overview 5.2 Physical Calibration 5.3 Internal Quality Assurance 5.4 External Quality Assurance 5.5 Servicing 5.6 Planned Preventative Maintenance 6. Protocols & Procedures 6.1 Laboratory Protocol Manual 6.2 Administration of Medications 6.3 Consent 7. Documentation 7.1 Referral forms 7.2 Referral information 7.3 Appointment Letters 7.4 Reporting & Interpretation 7.5 Quality Assurance of Test Results 7.6 Format of Results 7.7 Storage of Records 7.8 Reference equations 8. Laboratory Accreditation Scheme 9. Summary of Action Points 10. Consultation Process References Appendix 1 Executive Summary Appendix 2 ARTP Working Groups Appendix 3 Levels Of Evidence Appendix 4 Generic Report Format 1. ARTP WORKING GROUPS This is the first of a series of position papers produced by the ARTP (see Appendix 2) on inter-related topics the contents of which all have a bearing on quality in the respiratory laboratory This paper should be read in conjunction with these other papers to gain a global perspective. The recommendations produced as a result of these Working Groups will also be used to formulate criteria for a laboratory accreditation scheme. The recommendations for best practice in this document have been compiled as consensus opinion after wide consultation with interested parties. Any published evidence base is provided where available. 2. SCOPE OF THIS DOCUMENT The scope of this document is limited mainly to routine Pulmonary Function Tests (PFT s) and some associated non-routine procedures but similar principles should be applied to any other testing procedures undertaken within a Clinical Physiology (CP) department. Respiratory diagnostic testing is usually undertaken by clinical physiologists but may also be performed by clinical scientists, respiratory specialist nurses and, increasingly, spirometry is being undertaken by occupational health nurses and nurses in general practice. Where the term physiologist is used in this document it is intended to include any healthcare practitioner performing diagnostic testing. 3. INTRODUCTION Quality Assurance (QA) is essential to measure and monitor the accuracy of results obtained during respiratory function testing. As the results obtained during testing can have a direct effect on patient treatment, and hence clinical outcomes, effective QA in respiratory diagnostics is a vital component of clinical governance. Overall responsibility for QA within a laboratory will usually lie with the most senior Clinical Physiologist. The main guidelines 1 used until now in the UK gave very little guidance on QA with few other papers covering the topic comprehensively 2-4. The new ATS/ERS joint statements 5-9 on pulmonary function have just been published at the time of writing this paper. These statements suggest techniques for quality control of equipment which may be adapted for general use. ARTP Working Group Quality Page 1 of 14 ARTP, April 2006

2 The primary factors causing variation in test results can be identified as staff, equipment and protocols. Errors introduced into the testing process by any of these elements can be minimised by the application of training standards, equipment maintenance and by adhering to published protocols for testing. (C) This paper makes recommendations for good practice and also discusses other related topics (eg request forms & results sheets) which can have a significant effect on the quality of testing outcomes due to the poor conveyance of information. Throughout this document recommendations for good practice are marked with this symbol. 4. STAFFING The most important component in successful spirometry is a well-motivated, enthusiastic technician 10 Although not discussed in detail in this paper (this will be addressed in another forthcoming ARTP Working Group statement see appendix 2) the contribution of the human part of the lung function laboratory equipment should not be underestimated. In most laboratories in the UK, PFT s will be performed by clinical physiologists. This relatively new term has been proposed as a protected title for this staff group which has been now been put forward for statutory regulation as independent practitioners under the Health Professions Council. Just over half of the NHS hospitals providing a respiratory function service are single (ie respiratory) speciality, the majority of the other departments are joint cardio-respiratory (Source: ARTP Survey 2005). There is concern that, in some multidisciplinary departments, respiratory function is split among a number of physiologists who may only practice for a small percentage of their working week. This dilutes the practical clinical experience of each individual and may therefore have quality implications. Whilst acknowledging that single speciality departments are not always practical in every type of hospital, it would be preferable that practitioners performing respiratory tests within a multidisciplinary unit should spend an appreciable amount of time performing this role, and that their professional development in the discipline is supported, so that their practical experience is not limited. At least one practitioner should take a lead role and spend the majority of their time in respiratory physiology and have fulfilled the training criteria discussed in section Training To ensure a minimum level of competent practice, within any laboratory, there should be at least one staff member who either holds the ARTP National Assessment qualifications or can demonstrate relevant experience through professional registration and who will take lead responsibility for respiratory clinical physiology. Education, training, assessment of competence, continuing professional development and other factors that affect the staff who perform the full battery of tests provided in the respiratory physiology laboratory will have a significant effect on quality. Ongoing CPD is important to update and maintain staff competence and develop the service and should be encouraged. Staff and education issues will be addressed in more detail in other ARTP Working Group Reports (appendix 2). 5. EQUIPMENT 5.1 Overview The American Thoracic Society published standards for spirometers in and Hankinson et al. 12,13 devised waveforms with which to test spirometers response. These tests were deemed compulsory before any spirometer could be marketed in the United States and although questionable in some respects, have at least standardised, and reduced, equipment variability. Although there are now devices that can deliver a known standard result (eg the iso-thermal flask for plethysmography and, more recently, a standardised transfer factor apparatus 14 ) there are no similar requirements for manufacturers to standardise the design of equipment for other PFT parameters. It has been demonstrated that variability of measurements exist between different manufacturers equipment when tested on a simulator and that variability is greater still on normal subjects 15,16. (B) The accuracy of testing relies on the use of equipment specified as diagnostic quality rather than equipment intended for monitoring purposes. Recent advances in technology are producing good compact home monitoring devices, that are able to measure not only peak flow but also other spirometric parameters such as FEV 1. The use of these devices as a diagnostic tool is not advised and should be limited, like the mechanical mini-wrights peak flow meter, to monitoring serial trends in a single subject. Laboratories will usually perform regular calibration checks (and should also run a physiological control program). However the calibration frequency reported by different laboratories varies. In this document some minimum frequencies are recommended as a minimum standard which should be modified according to local practice and experience. The ARTP has a Manufacturers Liaison Committee (MLC) which works closely with the providers of PFT (and related) equipment. Some of the recommendations in this paper have already been suggested to manufacturers and need to be implemented. The MLC will encourage further compliance with these recommendations. ARTP Working Group Quality Page 2 of 14 ARTP, April 2006

3 The MLC can be contacted via through to mediate in any issues concerning the quality of service provided by companies dealing in respiratory equipment and services. 5.2 Physical Calibration Calibration is the correlation of the reading of an instrument with a standard whereas verification establishes the correctness of a reading by demonstration 17. The important distinction between these two procedures is that calibration will alter the gain and/or offset of an instrument s measurement but verification only checks that an instrument is reading within certain parameters. On some equipment it may only be possible to perform a verification of the calibration, if this type of instrument fails its verification it can only be withdrawn from use until it has been properly serviced. It therefore follows that calibration of an instrument has the potential to introduce extraneous errors into the measurement and that calibration procedures should only be performed by competent staff with a good knowledge of instrumentation using a verifiable standard as a reference. Calibration, or at least verification, of the parameters being measured should take place on a regular basis. The frequency of these calibration procedures will depend on the actual parameter being measured, the known stability of the equipment and the number of patients being measured. The ideal frequency of calibration or verification may have to be balanced against practicalities. While manufacturers recommendations must be taken as a baseline the minimum frequency considered necessary for the calibration of different types of common PFT equipment is detailed in Table 1. Table 1: Minimum Calibration Frequencies Volume displacement spirometers (including leak test) Mechanical time Flow measuring spirometers Lung Volumes (Dilution/Washout Methods) Plethysmograph - box volume - mouth pressure - leak test Gas Analysers - zero - span - linearity Daily/Sessional Quarterly Daily/Sessional Monthly Daily/Sessional Before each test Daily/Sessional Quarterly Volume calibration should ideally be checked over a span of at least 3 litres volume. Calibration syringes should be kept near to the equipment being checked or allowed to equilibrate to local conditions to reduce any temperature errors. Limits of acceptability are ±3.5% or 65 mls, whichever is the greater 6. Where manufacturers recommendations for tolerance are smaller these should be used. If the temperature changes significantly (the BTPS conversion factor changes by about 0.5% per degree; changes in barometric pressure are less significant) during the course of a testing session it is necessary to re-check the calibration. On flow measuring devices volume calibration should be checked at different flow rates (eg low, medium & high within the physiological range for example 1, 3 & 9 litres per second). Calibration should always be checked following cleaning or other maintenance procedures. The accuracy of calibration syringes should be checked by the manufacturer annually. Calibration & QA data for all PFT laboratory equipment should be documented in a form which will enable users to spot any errors that may develop over time. On some machines this may be stored by software such programs should allow the data to be accessed and presented in an easy to interpret form. Overall the approach to physical quality control and the limits and tolerances suggested in the ATS/ERS joint statements are supported. Whilst not strictly a piece of PFT equipment, in many laboratories blood gas analysers (BGA s) are an essential tool. Modern machines automatically run regular calibration cycles and, in most hospitals, internal QC of the analyser is the responsibility of the Biochemistry Dept. Where BGA s are maintained by physiologists a QC program, as would be expected for Clinical Pathology Accreditation (CPA), should be in place. Action Point: (5.2): ARTP Manufacturer s Liaison Committee (MLC) to discuss costs of syringe calibration, and possibility of service exchange, with manufacturers to make this more feasible. 5.3 Internal Quality Assurance Though there are now devices available (previously mentioned) that will deliver standard values for most of the common lung function parameters they are not within the scope of the ordinary lung function laboratory s budget. The only practical, and accessible, way of testing a laboratory s testing procedures as a whole system is the use of normal volunteers as physiological controls. Ideally these subjects should be healthy non-smokers. Measurements of PFT parameters on these subjects should be made at least weekly and recorded in a format that can identify trends and limits. Measurements outside of a range of ±2 standard deviations defines a point at which acceptable variability is exceeded and investigation, and corrective action, is required 4. This approach does require that an individual first builds up a reasonable number of readings from which ARTP Working Group Quality Page 3 of 14 ARTP, April 2006

4 their own reference mean and standard deviation can be calculated. Consistency of measurements over time is important especially when looking at serial trends of patient results. The same approach is also valid for QA of exercise testing equipment 18, though the frequency of physiological control studies would be moderated by the actual number of diagnostic tests being performed in the laboratory. Departments should run a regular internal physiological control programme using more than one readily available member of staff who should be known to be free from any respiratory problems. According to Cotes 19 generally a coefficient of variation (CoV) of 4-8% could be expected in labs with high standards though some tests are more reproducible than others. The Lung Health Study 10 demonstrated that a CoV of 5.8% for FEV 1 was achievable in a general population when good QA was applied. This was half the CoV in the other published studies with which they compared their data. When Wanger and Irvin 20 compared 13 labs in the Denver area they found considerable inter-laboratory variation which they attributed mainly to variation in practice. (C) The SAPALDIA study 21 separated out machine & operator effects for spirometry which demonstrated that slightly more variance was attributable to using different operators than between virtually identical spirometers. Comparison of their data with other studies showed that 2-4% CoV should be achievable for spirometry within a single laboratory s quality assurance monitoring. (C) Robson & Innes 22 demonstrated a natural variability of ±1.84 SI units for transfer factor, ±0.28 for KCO, in healthy volunteers. Though the authors of this paper do not favour the use of percentages to describe variability in a general population it can be deduced that in a healthy individual this variability may exceed 10%. (C) For lung volumes measured by Plethysmography the ATS/ERS statement on lung volumes does not report an actual CoV but states that 10% difference in FRC and TLC for physiological control subjects is twice what should be achievable. (C) The same body of evidence for other lung function parameters does not seem to be available, however inter-laboratory studies (see Section 5.4) that have been performed as part of the ARTP Regional QA Scheme and also by the ANZSRS give an indication of what should be achievable in a single location. Some Manufacturers have designed QA software into their systems but this is often found to be inadequate (and also not helpful if a laboratory uses machines from different manufacturers). Action Point: (5.3a): ARTP Manufacturers liaison Committee to discuss with manufacturers developing a recommendation for QA documentation within software of systems supplied in the UK. Action Point: (5.3b): ARTP to develop a recommendation for recording QA. 5.4 External Quality Assurance Whilst it is expected that different equipment within a lab would be cross-checked for internal consistency, labs should also compare themselves with other labs within their locality. Participation in the ARTP Regional QA scheme provides a mechanism for this type of inter-laboratory comparison. The effort required to complete a regional audit of laboratories limits the frequency at which these checks can be conducted. So laboratories should also crosscheck their results with more than one other lab when Table 2: Summary of Reported Coefficients of Variation for PFT Parameters Inter-laboratory Lung Health Sapaldia b Denver West Mids South West ANZSRS Study a 1991 f 2001 c 2004 d 2001 e FVC 2.7% % 3.5% 4.3% 3.7% FEV 1 5.8% 3.3% % 3.3% 3.7% 4.1% PEF 7.5% 8.0% 5.1% FRC % 11.1% 11.5% 12.8% TLC % 4.8% 5.5% 5.1% TLco ~% 7.8% 12.0% 7.7% Intra-laboratory Sapaldia b Denver ATS/ERS Jensen et ARTP 1991 f 2005 g al. h Target FVC 2.0% % 4% FEV 1 2.2% 2.7% % 4% PEF 8% FRC 12% TLC % 6% TLco % 9% % 8% a. Lung Health Study 10 b. Kunzli et al 21 c. Watts et al 23 d. ARTP South West Regional Group e. Swanny et al 24 f. Wanger & Irvin 20 g. ATS/ERS h. Jensen et al 15,16 ARTP Working Group Quality Page 4 of 14 ARTP, April 2006

5 major changes take place (eg acquisition of new equipment) or/and, alternatively, carry out a comparative study of new vs. old equipment to determine whether there are any differences. Laboratories should endeavour to improve upon the targets summarised in table 2. The recent longitudinal studies by Jensen et al have shown variation of 2.8% to 4.2% in FEV 1 and 4.9% to 9.8% in DL co between 5 different manufacturers equipment. It can therefore be assumed that, where laboratories are using different manufacturers equipment, inter-laboratory variance will be a little greater than would be expected within a single laboratory using a single manufacturer s equipment. (C) Where different manufacturer s equipment is used within the same laboratory it is recommended that any patients being monitored over time are tested on the same equipment at each visit, and ideally at the same time of day, in order to minimise this variance. 5.5 Servicing Basic responsibilities for dealing with electrical equipment are laid out in the Health & Safety at Work Act and other Statutory Regulations 25,26,27. Servicing of electro-medical devices in NHS institutions is the responsibility of the local electro-biomedical engineering department. However, having more indepth knowledge of the instrumentation and associated issues the head of the Clinical Physiology department is also responsible for ensuring that the servicing that is in place is appropriate. Due to the specialised nature of the equipment, servicing should be carried out by the manufacturer, or an engineer certified by the manufacturer, and at the manufacturer s recommended intervals. Documentation of manufacturers service visits should be kept, including any calibration certificates, software upgrades and engineers reports. Maintaining a service history for each item of equipment is good practice as it may reveal recurrent problems or deteriorating function. This includes both laboratory and domiciliary loan equipment (eg nebuliser compressors and nasal CPAP units). An up to date inventory of all electrical equipment including physical location and service due dates should be maintained. 5.6 Planned Preventative Maintenance The department should operate a planned preventative maintenance (PPM) schedule to ensure that any user or first-line maintenance procedures recommended by the manufacturer are carried out at the appropriate intervals. A departmental PPM Manual should summarise the required procedures and the frequency at which they should be performed (including any cleaning /infection control procedures). Log sheets should document performance of the tasks specified, including recording when equipment is serviced or checked by engineers from the manufacturer or local medical engineers. It is good governance that the records kept should identify exactly when a procedure was carried out and which individual performed it. These procedures may need to be modified due to local knowledge; for example the frequency of calibration checks, or replacement of a component, may need to be increased due to a machine s history of instability. Laboratory down-time must be scheduled to allow access to equipment for QA, cleaning and PPM procedures. Action Point: (5.6a): ARTP to make recommendation on format for PPM schedules. Action Point: (5.6b): MLC to pursue specification of service contracts. 6. PROTOCOLS & PROCEDURES 6.1 Laboratory Protocol Manual All departments should have a written set of protocols covering all the procedures performed. This serves as a central source of reference and ensures that all staff are aware of any risks and any local variance from nationally accepted standard practice. The current main reference sources for standard UK practice are the 1994 BTS/ARTP Guidelines 3 and the ARTP Part One and Part Two Handbooks 28,29 which cover the main practical considerations for test procedures, such as criteria for acceptability and reproducibility. These will probably be refined in line with the recently published ATS/ERS guidelines. General topics (eg Health & Safety, CoSHH etc) will be covered by controls assurance systems within the trust or establishment but specifics risks pertaining to any test procedures should also be highlighted (and crossreferenced to detailed risk assessments) within this Laboratory Protocol Manual. This set of documents should include (for each procedure) :- Rationale & Evidence base Practical protocol Contra-indications (relative and absolute) Any risks to the practitioner/patient Any cleaning/maintenance protocols Local deviations from standard practice While it is acknowledged that variation from standard accepted practice is likely to occur the reasons for this should be justifiable and documented. Action Point: (6.1): ARTP to produce a generic protocol manual which can be adapted for local use. ARTP Working Group Quality Page 5 of 14 ARTP, April 2006

6 6.2 Administration of Medications The Health Service Circular 2000/ recommends that Patient Group Directions should be employed where medications are given to patients without a named prescription. Clinical physiologists were omitted from the list of healthcare professionals to which this document applied. Despite this omission, it should be considered good practice to develop local PGD documentation to conform to this recommendation when administering medications for the purpose of testing (eg bronchodilators). Action Point: (6.2): ARTP to make a recommendation on generic PGD s for bronchodilator administration during PFT s Administration of any medication should be documented on the test results, recording dose and method of delivery. 6.3 Consent According to Dept of Health Guidance 31, as a result of case law, it is necessary to inform the patient of any material or significant risks in the proposed treatment, any alternatives to it, and the risks incurred by doing nothing. For certain risk-prone procedures (eg Cardio Pulmonary Exercise Testing, Histamine/Methacholine Challenge, Hypoxic Challenge) it may be necessary to obtain consent. There are currently no firm guidelines relating to respiratory function investigations so advice on whether the required consent can be implied or is required in verbal, or written, form should be sought from the local clinical governance team. Action Point: (6.3): ARTP to develop statement on consent for respiratory physiology procedures. 7. DOCUMENTATION 7.1 Referral forms For patient safety, to ensure that appropriate tests are performed, and to enable the laboratory to properly prioritise and allocate workload & resources, referral forms (whether paper-based or electronic) require a certain minimum amount of information. The patient must be uniquely identifiable by name & hospital, or NHS, number and/or date of birth. If date of birth is not available age should be included. The patient s identity should be verified at the point of testing. The location of the patient must be clear; if they are an outpatient the full address should be provided. If they are an inpatient, which ward. However if it is intended that the tests be performed as an outpatient after discharge this needs to be clearly stated. The referring consultant s team needs to be included so that results and reports can be returned promptly. The reason for a request should be clear from the clinical information provided which should include any known, or suspected, diagnoses. Elements of the subject s previous medical history may also be important and current medication, especially any that may be relevant to the interpretation of the results, must be included. Any known infection risks 32 or any contraindications 6 need to be brought to the attention of the physiologist prior to testing to ensure patient safety. Including the next outpatient appointment date on referral forms may help to ensure that tests can be booked either at, or before, the visit or so that the results are available for the consultation. Where administration of a prescription medication is required as part of the test procedure the signature of a referring physician is required (see Section 6.2 HSC2000/026). A signature should also be obtained for any procedures that carry any increased level of risk (eg Challenge Testing) 7.2 Referral information On receipt of a request form the information should be reviewed to determine whether the requested tests are appropriate to answer the clinical questions. Local protocols should determine whether the physiologist may modify the requested tests or whether the form should be returned to the referrer, or the lead respiratory physician, to authorise any suggested changes. Adequate patient details to uniquely identify a patient and sufficient clinical details to allow assessment of the appropriate tests and permit correct interpretation of the results (to aid reporting) should be included on a referral form. This is a patient safety issue and forms with insufficient details should be returned to the referrer to be completed properly. Referral forms which are illegible or ambiguous should also be returned to the referrer. Forms need to distinguish a routine referral from an urgent referral to fast track an appointment when a result is needed quickly. If the patient is not able to make their own way to the laboratory it aids staff making appointments to know the patient s mobility. The authorisation for booking hospital transport will be covered by local protocols but, where laboratory staff are requested to make the booking, authorisation from a physician who has assessed the patient s mobility is usually required. 7.3 Appointment Letters Appointment letters need to give the following details: Date and time of appointment Location of the department (if there are more than one hospital in the trust ensure it is clear which hospital) ARTP Working Group Quality Page 6 of 14 ARTP, April 2006

7 Lab Contact Details (eg tel. no. for rescheduling of appointments, general enquiries, etc) Expected duration of the appointment Pre-attendance advice 3 (particularly with regard to with-holding medication) Any patient preparation advice (eg bringing suitable clothes for exercise tests) Where there are consent issues it may be appropriate to enclose information specifically written to ensure that the patient is fully informed of the intended procedure before attending. Any patient information literature generated by a department should conform with the Department of Health recommendations 33 which are specific about the fonts and style that should be used. 7.4 Reporting & Interpretation There is a distinction to be made between the three different types of comments that may be attached to a set of test results. Technical comments should (and can only) be made by the physiologist who actually performs the test. In the case of a trainee physiologist this would be subject to review by the supervising physiologist. A technical comment should be made on every set of tests presented for reporting. Technical reporting could be undertaken by a physiologist with sufficient experience, in future this would be a State Registered Respiratory Clinical Physiologist or equivalent grade. A technical report would make statements of fact based on rigid criteria; for example, a technical report might state mild airways obstruction with 20% improvement in FEV1. Clinical reporting would usually be performed by consultant or SpR physicians but may also be expected of senior physiologists, clinical scientists and, in some areas, respiratory specialist nurses (usually Band 7 or higher). Staff performing this extended role should have their competence assessed by a training framework approved by the local clinical governance structure and included within a scope of practice (SOP). Clinical reporting involves interpretation of the results with respect to a clinical condition. For example, a clinical report may say that the results suggest asthma and may also possibly suggest further treatment or investigations (eg steroid trial). Interpretation of results is improved by considering all aspects of the patient s clinical status. When available, radiographic findings, haemoglobin values, previous PFT results and other clinical details should be taken into consideration. The ATS/ERS statement on interpretative strategies 9 gives more detail on reporting and interpretation of pulmonary function results. Due to the enforced periods between tests where inhaled test gas has to wash out there is time to chat to the patient. Dialogue between the reporter and the physiologist performing the test, whether written or verbal, can reveal extra clinical information that has been disclosed during the course of testing but omitted during a clinic consultation. Clinically relevant information revealed during testing session should be passed on to the referring clinician. This time can also be used to deliver health education advice (eg smoking cessation). 7.5 Quality Assurance of Test Results A senior member of staff should review all of the results passing through the lab to identify any trends that may not be noticed by an individual practitioner. Review of the reports being generated as a result of the tests should also be performed, especially where the reporter is in a training post (eg Specialist Registrars). Regular monitoring and feedback of test quality has been shown to improve consistency 5,10. Regular review of a practitioner s performance is recommended. Information for monitoring individual test quality may already be available within a laboratory s test equipment software and may be used to make an objective assessment of the performance of a set of tests. Automated reporting systems should not be used for issuing technical reports unless the reports have been verified by a clinical reporter. A statement to this effect should be printed (in the comments section) of any automated report. 7.6 Format of Results Results and, where possible, any comments/reports should be printed and stored on the computer software. If handwritten, reports should be legible. A final report (this would also include any version stored electronically) should contain at least the following components A unique patient identifier (typically at least name and hospital, or NHS number) Ethnic Origin Height, Weight and/or BMI A Flow Volume Loop and/or Volume Time Curve graphic (to allow review of patient compliance) The equipment and technology (eg plethysmography, helium dilution, nitrogen washout for lung volumes) used should be identifiable For each parameter o The best values (selected according to guidelines) o Best values expressed as % predicted o The range of reference values or, preferably, standardised residuals o Units of measurement Technical comments o a measure of the reproducibility (this may be contained in the technical report) o The test substance, dosage and delivery method used for any reversibility testing ARTP Working Group Quality Page 7 of 14 ARTP, April 2006

8 o The physiologist who performed the test should also be identifiable Clinical/Technical report o Variation from expected values o Signature Whether ethnic corrections have been applied (See reference equations ) Optional components Medication history Smoking history To establish accountability, when using electronic documents, a digital signature would need to be used on clinical reports if there is no hard copy of the final report. However, at the time of writing, we are not aware of any specification for the national electronic patient record (EPR) which covers this. ARTP recommends the use of Standardised Residuals as a method to easily identify deviation of a patients results from reference values and also for serial monitoring over long periods. A recommended format of results has previously been published and distributed to manufacturers of PFT equipment although the option has not yet been included as a standard report format on most equipment. A revised generic report format is presented in this document at Appendix 4. Action Point: (7.6): MLC to Re-distribute and encourage provision of SR reports as an option in equipment software supplied in the UK. 7.7 Storage of Records Paper documents (results, questionnaires, computer printouts, etc) should have a unique patient identifier, ideally patient and number, on every sheet so that any single sheets that get separated from the main patient record can be filed correctly. Copies of results and reports should be accessible within the department to enable quick retrieval of reports. This storage might be in paper or electronic form. When the storage is electronic, regular backups should be made of stored data and stored in a location away from the original source. The recommended system for data backup is to keep at least 2 copies, erasing the oldest each time a new backup is performed, this minimises data loss in the event of a failure of the backup media. Generally copies of medical records should be retained for a minimum of eight years after conclusion of the last treatment or the patient s death. In the case of children and young people they should be retained until the patient is at least 25 years old. However new (compared with previous guidance) categories of records that may apply to diagnostic laboratories, and their respective periods of retention, were defined in the Records Management: NHS Code of Practice 34 published in April 06. These are summarised in Table 3. There are many other categories of health record and which may supersede those summarised here e.g. when the records relate to research or litigation. A local Health Records Committee and/or Health Records User Group should be available to advise. 7.8 Reference equations For correct interpretation of results generated by the testing process it is important to select reference values and limits that are appropriate to the local population. The ECCS standards 35,36 recommend that laboratories should compare a local set of 'normal' subjects to the chosen reference set in order to validate if for use with their own population. Whilst acknowledging some deficits, mainly due to the age of the studies, the ARTP still recommends the ECCS equations for adult reference values (as listed in the BTS/ARTP 94 guidelines 3 ). (A) However the Rosenthal equations are considered more appropriate for paediatric reference values 37,38. This is because extrapolation errors occur when the ECCS equations are extended below certain ages and the linear algorithms do not take into account the growth changes during puberty. (C) There is still debate about the correction of reference values to account for ethnic differences. The broad statement in the BTS/ARTP 94 guidelines 3 that the predicted value should be multiplied by a factor of 0.9 for certain ethnic groups does not seem to apply across all ethnic origins 39. This is confounded in the UK by socio-economic changes in the first generation british-born members of immigrant families. More research in this area is needed. All reports should explicitly state whether, or not, an ethnic correction has been applied to the results presented. If a correction has been applied the magnitude of that correction should also be stated. Action Point: (7.8a): MLC to encourage manufacturers to make recommended reference sets available in current/future software option in equipment supplied in the UK. Action point (7.8b): More research into ethnic reference values is needed 8. LABORATORY ACCREDITATION SCHEME The ARTP is developing a laboratory accreditation scheme which will audit labs against a set of recommendations agreed with the British Thoracic Society. The standards will be determined by wide consultation via the ARTP Working Groups being enacted in Once established it would be expected that laboratories would submit themselves for accreditation at the recommended frequency and address any shortcomings identified with a formal action plan. Review Date: May 2009 ARTP Working Group Quality Page 8 of 14 ARTP, April 2006

9 Table 3: Partial Summary of Records Management: NHS Code of Practice TYPE OF HEALTH RECORD Day books and other records of specimens received by a laboratory Equipment/instruments maintenance logs, records of service inspections Procurement, use, modification and supply records relevant to production of products (diagnostics)or equipment External quality control records Internal quality control records Lab file cards or other working records of test results for named patients Near-patient test data Photographic records Request forms that are not a unique record Equipment validation QC documentation, certificates of analysis Standard operating procedures MINIMUM RETENTION PERIOD 2 calendar years Lifetime of equipment 11 years 2 years 10 years 2 calendar years Result in patient record, log retained for lifetime of instrument 30 years where images present the primary source of information for the diagnostic process 1 week after report received by requestor Lifetime of the equipment 5 years or 1 year after expiry of batch(whichever is longer) 15 years after superseded by revised version 9. SUMMARY OF ACTION POINTS Action Point: (5.2): ARTP Manufacturer s Liaison Committee (MLC) to discuss costs of syringe calibration, and possibility of service exchange, with manufacturers to make this more feasible. Action Point: (5.3a): ARTP Manufacturers liaison Committee to discuss with manufacturers developing a recommendation for QA documentation within software of systems supplied in the UK. Action Point: (5.3b): ARTP to develop a recommendation for recording QA. Action Point: (5.6a): ARTP to make recommendation on format for PPM schedules. Action Point: (5.6b): MLC to pursue specification of service contracts. Action Point: (6.1): ARTP to produce a generic protocol manual which can be adapted for local use. Action Point: (6.2): ARTP to make a recommendation on generic PGD s for bronchodilator administration during PFT s Action Point: (6.3): ARTP to develop statement on consent for respiratory physiology procedures. Action Point: (7.6): MLC to Re-distribute and encourage provision of SR reports as an option in equipment software supplied in the UK. Action Point: (7.8a): MLC to encourage manufacturers to make recommended reference sets available in current/future software option in equipment supplied in the UK. Action point (7.8b): More research into ethnic reference values is needed 10. CONSULTATION PROCESS This report was open for consultation on the ARTP website during February/March The membership of the ARTP consists of all grades of staff; Clinical Physiologists, Clinical Scientists, Nurses and Physicians working in Respiratory Physiology services including representatives of Equipment Manufacturers. Particular thanks are also due to the ARTP Advisory Board and ARTP members who contributed in the early stages at the Stratford-on-Avon Conference Workshops and Quality Assurance Scheme Launch Day. ARTP Working Group Quality Page 9 of 14 ARTP, April 2006

10 REFERENCES 1 Guidelines for the measurement of respiratory function. Recommendations of the British Thoracic Society and the Association of Respiratory Technicians and Physiologists. Respir Med Mar;88(3): Crapo RO. Spirometry: Quality Control and Reproducibility Criteria. Am Rev Respir Dis 1991; 143: Wanger J. Quality Assurance. Respir Care Clin N Am Jun;3(2): Gardner RM, Clausen JL, Crapo RO, Epler GR, Hankinson JL, Johnson Jr RL and Plummer AL. Quality assurance in Pulmonary Function Laboratories. Am Rev Respir Dis 1986;134: Brusasco V., Crapo R. and Viegi G. Coming together: the ATS/ERS consensus on clinical pulmonary function testing. Eur Respir J 2005; 26: Miller MR, Hankinson J, Brusasco V, Burgos F, Casaburi R, Coates A, Crapo R, Enright P, van der Grinten CP M, Gustafsson P, Jensen R, Johnson DC, MacIntyre N, McKay R, Navajas D, Pedersen OF, Pellegrino R, Viegi G and Wanger J. Standardisation of spirometry. Eur. Respir J 2005; 26: Wanger J., Clausen JL, Coates A, Pedersen OF, Brusasco V, Burgos F, Casaburi R, Crapo R, Enright P, van der Grinten CPM, Gustafsson P, Hankinson J, Jensen R, Johnson D, MacIntyre N, McKay R, Miller MR, Navajas D, Pellegrino R and Viegi G. Standardisation of the measurement of lung volumes Eur Respir J 2005; 26: MacIntyre N, Crapo RO, Viegi G, Johnson DC, van der Grinten CPM, Brusasco V, Burgos F, Casaburi R, Coates A, Enright P, Gustafsson P, Hankinson J, Jensen R, McKay R, Miller MR, Navajas D, Pedersen OF, Pellegrino R and Wanger J Standardisation of the single-breath determination of carbon monoxide uptake in the lung. Eur Respir J 2005; 26: Pellegrino R, Viegi G, Brusasco V, Crapo RO, Burgos F, Casaburi R, Coates A, van der Grinten CPM, Gustafsson P, Hankinson J, Jensen R, Johnson DC, MacIntyre N, McKay R, Miller MR, Navajas D, Pedersen OF and Wanger Interpretative strategies for lung function tests. Eur Respir J 2005; 26: Spirometry in the Lung Health Study: methods and quality control. Am Rev Respir Dis 1991; 143: American Thoracic Society. Standardization of Spirometry, 1994 Update. Am J Respir Crit Care Med Sep;152(3): Hankinson JL, Gardner RM. Standard waveforms for spirometer testing. Am Rev Respir Dis 1982;126(2): Hankinson JL, Reynolds JS, Das MK, Viola JO. Method to produce American Thoracic Society flow-time waveforms using a mechanical pump. Eur Respir J 1997;10(3): Crapo RO, Jensen RL. Standards and Interpretive Issues in Lung Function Testing Respir. Care August 2003 Vol 48 No 8 15 Jensen R. L., Teeter J. G., England R. D., Pickering E. H., Howell H. M., Crapo R. O. Instrument performance in the longitudinal measurement of diffusing capacity (DL co) ERJ2004;Vol.24;Supp S 16 Jensen R. L., Teeter J. G., England R. D., White H.J., Pickering E. H., Crapo R. O. Performance of 5 PFT Instruments in the longitudinal measurement of FEV 1. Eur Respir J 2004;Vol.24;Supp S 17 The Concise Oxford English Dictionary 8 th Ed. Oxford University Press 18 Revill SM, Morgan MD Biological quality control for exercise testing. Thorax Jan;55(1): Cotes JE Lung Function Assessment & Application in Medicine 5 th Ed. Blackwell Scientific Publications 20 Wanger J, Irvin C. Comparability of pulmonary function results from 13 laboratories in a metropolitan area. Respir Care Dec;36(12): Kunzli N, Ackermann-Liebrich U, Keller R, Perruchoud AP, Schindler C, SAPALIA Team. Variability of FVC and FEV 1 due to technician, team, device and subject in an eight centre study: three quality control studies in SAPALDIA. Eur. Respir. J. 1995, 8, Robson AG, Innes JA. Short term variability of single breath carbon monoxide transfer factor. Thorax 56: 2001: Watts TP, Butterfield AK, Moore AJ, Marshall T. How Accurate are your Respiratory Function Results? A Quality Assurance Audit of Respiratory Function Laboratories within the West Midlands. Inspire Dec 2005; 6(3): Swanney M, Guy P, L Cardno, C Frampton, K Gain, D Sharp & L Beckert. Interlaboratory variability in the measurement of lung function in Australia & New Zealand. Proceedings of ANZSRS ASM, Health & Safety at Work Act The Provision and Use of Work Equipment Regulations (PUWER) Medical Device Equipment Management for Hospitals and Community-Based Organisations. MDA DB ARTP Handbook Part 1. 2 nd Ed. ARTP 29 ARTP Handbook Part 2. 1 st Ed. ARTP 30 Patient group directions [England only], Health Service Circular 2000/ Reference Guide to Consent for Examination or Treatment. Department of Health March 2001 ( 32 Kendrick AH, Johns DP, Leeming JP. Infection control of lung function equipment: a practical approach. Respir Med Nov;97(11): Dept of Health Patient Information Toolkit ( 34 Records Management: NHS Code of Practice /1 (Part 1) and /2 (Part 2): Dept of Health. April Quanjer PhH. Standardised lung function testing. Report Working Party for the European Community for Steel and Coal. Eur Resp J 1993; 6: Suppl Quanjer PhH, ed. Standardization of lung function tests 1993 Update. Report Working Party for the European Community for Steel and Coal. Bull. Eur. Physiopath Respir 1983; 19: Suppl Rosenthal M, Cramer D, Bain SH, Denison D, Bush A, and Warner JO Lung function in white children aged 4 to 19 years: I-- Spirometry Thorax, Aug 1993; 48: Rosenthal M, Cramer D, Bain SH, Denison D, Bush A, and Warner JO Lung function in white children aged 4 to 19 years: II-- Single breath analysis and plethysmography Thorax, Aug 1993; 48: Moore AJ, Lone IM, Khair OA. ECCS/ERS reference values for spirometry are they still applicable? Eur Resp J Vol 24 Suppl 48 ARTP Working Group Quality Page 10 of 14 ARTP, April 2006

11 APPENDIX 1 EXECUTIVE SUMMARY ARTP Working Groups on Standards of Care and Recommendations for Lung Function Departments (2006) Quality Assurance For Lung Function Laboratories ARTP Working Groups This is the first in a series of position papers produced by ARTP. The recommendations produced as a result of this series will define standards in respiratory physiology and be used to formulate criteria for a laboratory accreditation scheme. Introduction Respiratory diagnostic testing is usually undertaken by clinical physiologists but other staff groups may also perform these procedures. Quality Assurance is essential to measure and monitor the accuracy of results obtained during respiratory function testing and can directly impact on clinical outcomes. The primary factors causing variation in test results can be identified as staff, equipment and protocols. Errors introduced into the testing process by any of these elements can be minimised by the application of training standards, equipment maintenance and by adhering to published protocols for testing. Staffing & Training At least one staff member in a laboratory should either hold the ARTP qualifications or demonstrate relevant experience through professional registration and take lead responsibility for respiratory clinical physiology. General staffing issues are discussed in more detail in other papers in this series. Practitioners performing respiratory tests within a multi-disciplinary unit should spend an appreciable amount of time performing this role. At least one practitioner should take a lead role and spend the majority of their time in respiratory physiology and have fulfilled the appropriate training criteria. Ongoing CPD is important to update and maintain staff competence and develop the service and should be encouraged. Equipment Equipment used should be of diagnostic quality. Calibration of an instrument has the potential to introduce extraneous errors into the measurement and calibration procedures should only be performed by competent staff. In this document minimum standards are recommended for calibration frequencies. Factors which may affect calibration are discussed. The approach to physical quality control and the limits and tolerances suggested in the ATS/ERS joint statements are broadly supported. Internal QA using normal volunteers as physiological controls is recommended at least weekly with monitoring of variability. Laboratories should compare their results with other labs within their locality. A mechanism for this is the ARTP Regional QA scheme. Target CoV values are suggested for monitoring intra- and inter-laboratory variation. Servicing should be carried out by the manufacturer, or an engineer certified by the manufacturer, and at the manufacturer s recommended intervals. The ARTP Manufacturers Liaison Committee (MLC) will encourage compliance with recommendations in this paper and mediate in any issues concerning the quality of service provided by companies. An up to date inventory of all electrical equipment including physical location and service due dates should be maintained. Departments should operate a planned preventative maintenance (PPM) schedule to ensure that any user or first-line maintenance procedures recommended by the manufacturer are carried out at the appropriate intervals. Laboratory down-time must be scheduled to allow access to equipment for QA, cleaning and PPM procedures. Protocols & Procedures Departments should have a Laboratory Protocol Manual covering all the procedures performed. Any variation from standard accepted practice should be documented. Clinical physiologists were omitted from the list of healthcare professionals to which Patient Group Directions applies. Despite this omission, it should be considered good practice to develop local PGD documentation where necessary. ARTP Working Group Quality Page 11 of 14 ARTP, April 2006