This study assessed the extent to which laboratory methods recommended by the Centers for Disease Control and Prevention were used in tuberculosis testing of patients in California in 1998. While recommended methods were used for most patients, there was room for improvement by hospital and independent non-health maintenance organization laboratories

Chin, Daniel P.

Desmond, Edward

Kellam, Steffi

Pascopella, Lisa

Reingold, Arthur

English

University of Montana

University of Montana ScholarWorks at University of Montana Public and Community Health Sciences Faculty Publications Public and Community Health Sciences 5-2001 Use of Recommended Laboratory Testing Methods Among Patients with Tuberculosis in California Steffi Kellam Lisa Pascopella University of Montana - Missoula, lisa.pascopella@mso.umt.edu Edward Desmond Arthur Reingold Daniel P. Chin Follow this and additional works at: https://scholarworks.umt.edu/pchs_pubs  Part of the Public Health Commons Let us know how access to this document benefits you. Recommended Citation Kellam, Steffi; Pascopella, Lisa; Desmond, Edward; Reingold, Arthur; and Chin, Daniel P., "Use of Recommended Laboratory Testing Methods Among Patients with Tuberculosis in California" (2001). Public and Community Health Sciences Faculty Publications. 13. https://scholarworks.umt.edu/pchs_pubs/13 This Article is brought to you for free and open access by the Public and Community Health Sciences at ScholarWorks at University of Montana. It has been accepted for inclusion in Public and Community Health Sciences Faculty Publications by an authorized administrator of ScholarWorks at University of Montana. For more information, please contact scholarworks@mso.umt.edu. JOURNAL OF CLINICAL MICROBIOLOGY,0095-1137/01/$04.0010 DOI: 10.1128/JCM.39.5.1969–1971.2001May 2001, p. 1969–1971 Vol. 39, No. 5Copyright © 2001, American Society for Microbiology. All Rights Reserved.Use of Recommended Laboratory Testing Methods amongPatients with Tuberculosis in CaliforniaSTEFFI KELLAM,1† LISA PASCOPELLA,1* EDWARD DESMOND,2ARTHUR REINGOLD,3 AND DANIEL P. CHIN1‡Tuberculosis Control Branch1 and Division of Mycology and Mycobacteriology,2 CaliforniaDepartment of Health and Human Services, and University of California atBerkeley School of Public Health,3 Berkeley, California 94704-1011Received 27 November 2000/Returned for modification 22 January 2001/Accepted 26 February 2001This study assessed the extent to which laboratory methods recommended by the Centers for Disease Controland Prevention were used in tuberculosis testing of patients in California in 1998. While recommendedmethods were used for most patients, there was room for improvement by hospital and independent non-healthmaintenance organization laboratories.The resurgence of drug-susceptible and multidrug-resistanttuberculosis (MDR-TB) in the United States between 1985and 1992 led to new recommendations that urged laboratoriesto use more rapid and accurate testing methods for diagnosingTB (2, 4). Studies assessing the use of recommended testingmethods for TB have consistently shown increases in the pro-portion of laboratories adopting rapid methods (1, 3, 5, 6).However, the extent to which laboratory-level improvementscorrelate with improvements at the patient level is unknown.TB testing services are gradually being consolidated in a small-er number of laboratories; consequently, a few laboratoriesusing less rapid testing procedures now have the potential todisproportionately affect the quality of testing for a large pro-portion of TB patients.In 1998, TB cases in California represented approximately20% of all the TB cases in the United States (Centers forDisease Control and Prevention [CDC], www.cdc.gov/nchstp/tb/surv/surv.htm). That year, we conducted a study to assessthe use of recommended testing methods for California pa-tients with culture-confirmed TB and to evaluate the testingprocedures of the mycobacteriology laboratories that per-formed the tests for those patients.Study population. The study population comprised 300 cul-ture-confirmed cases of TB reported to the TB control pro-grams in Los Angeles, Riverside, San Francisco, and SantaClara counties between 1 January and 31 December 1998. In1998, 48% of California’s TB cases were reported in thesecounties. We selected the first 75 culture-confirmed cases re-ported in each county during the study period. Because only 68cases were reported in Riverside County during 1998, 7 addi-tional cases were selected from Los Angeles County. Thesetwo counties are adjacent to each other and have similar pop-ulations.TB testing laboratories. Fifty-five separate laboratories wereidentified through patient records as having performed pri-mary TB testing for one or more of the study patients. If apatient had many specimens tested for TB, the specimen withthe earliest test result was selected for this evaluation. Thelaboratories that served the patient sample included 7 (13%)public health laboratories, 2 (4%) health maintenance organi-zation (HMO) laboratories, 11 (20%) independent non-HMOlaboratories, and 35 (64%) hospital laboratories. Laboratory-specific calculations are based on 54 laboratories becauseone hospital laboratory declined to participate in the study. Inaddition to patient-specific data, each laboratory was asked tocomplete a questionnaire concerning laboratory practices, in-cluding the range of testing services performed and monthlyvolume of specimens processed in that laboratory.Completeness of data. Information on the testing methodused was available for 268 (89%) of the 300 patients for smearmicroscopy, 265 (88%) of the 300 patients for mycobacterial* Corresponding author. Mailing address: California Department ofHealth Services, Tuberculosis Control Branch, 2151 Berkeley Way,Rm. 608, Berkeley, CA 94704-1011. Phone: (510) 540-3585. Fax: (510)849-5269. E-mail: Lpascope@dhs.ca.gov.† Present address: 155 Primrose La., Fredericksburg, TX 78624.‡ Present address: World Health Organization, 100600 Beijing,China.TABLE 1. Proportion of laboratories performing TB testing,compared with the proportion of TB patients testedby these laboratories, by laboratory typeTest and group Total no.No. (%) tested in differentlaboratory typesPublichealthIndependentnon-HMOHMO HospitalSmear microscopyLaboratories 44 3 (7) 8 (18) 2 (5) 31 (70)Patients 268 54 (20) 39 (15) 39 (15) 136 (51)Mycobacterial cultureLaboratories 43 4 (9) 8 (19) 2 (5) 29 (67)Patients 265 58 (22) 38 (14) 39 (15) 130 (49)Identification ofM. tuberculosisLaboratories 27 5 (19) 9 (33) 2 (7) 11 (41)Patients 272 83 (31) 61 (22) 40 (15) 88 (32)Drug susceptibilitytestingLaboratories 19 6 (32) 8 (42) 1 (5) 4 (21)Patients 266 99 (37) 82 (31) 23 (9) 62 (23)1969culture, 272 (91%) of the 300 patients for identification ofM. tuberculosis, and 266 (89%) of the 300 patients for drugsusceptibility testing. Unless otherwise noted, patient-specificanalyses are based on these denominators. Analyses were per-formed using SAS 6.12 (SAS Institute, Cary, N.C.). If infor-mation on a specific variable was missing for a laboratory or apatient, the laboratory or patient was excluded from analysesrelating to that variable; for this reason, denominators fordifferent analyses may vary.Comparison of laboratories performing TB testing and pa-tient specimens tested by those laboratories. In some cases, asmall proportion of the laboratories was responsible for testinga relatively large proportion of patient specimens for TB (Ta-ble 1). Public health and HMO laboratories accounted for,15% of the laboratories performing smear microscopy andmycobacterial culture, but they tested more than one-third ofthe patient specimens in our study population. Although most(60 to 90%) laboratories performing TB testing were eitherhospital or independent non-HMO laboratories, they per-formed a relatively smaller proportion of testing. Even so,these laboratories performed more than half of all TB testing.Use of recommended testing methods. Most of the studypatients were tested using CDC recommended methods (Table2). In general, the proportion of laboratories that performedTB testing using recommended methods correlated closelywith the proportion of patients tested using those methods (Ta-ble 3). However, differences in these proportions were notedfor smear microscopy, mycobacterial culture, and drug suscep-tibility testing. With regard to smear microscopy and culturetesting, hospital laboratories largely accounted for these dis-crepancies. For drug susceptibility testing in independent non-HMO laboratories, the proportion of patients tested usingBACTEC was lower than the proportion of laboratories thatused this method. These differences suggest that laboratory-level surveys may yield inaccurate estimates of the proportionof patients tested using recommended methods.Hospital laboratories that did not use recommended meth-ods for TB testing generally processed a lower volume of spec-imens (Table 4). Public health and HMO laboratories weremost likely to adhere to all of the recommended methods forTB testing. These laboratories generally processed large vol-umes of specimens for TB testing (.300 specimens per monthin most cases) and performed the full range of TB testing inhouse.Areas for improvement. Our results suggest that efforts tofurther expand the use of recommended methods for smearTABLE 2. Testing methods for smear microscopy, mycobacterialculture, identification of M. tuberculosis and drugsusceptibility testing of patient specimensProcedureaNo. (%) of patientspecimens testedusing indicatedmethodSmear microscopyFluorochrome* .................................................................. 243 (91)Carbol fuchsin.................................................................... 25 (9)Mycobacterial culture mediumLiquid*................................................................................ 73 (28)Solid .................................................................................... 17 (6)Both*................................................................................... 175 (66)Identification of M. tuberculosisNucleic acid probes*......................................................... 213 (78)BACTEC NAP* ................................................................ 4 (1)HPLC*................................................................................ 43 (16)Biochemical tests ............................................................... 0 (0)Nucleic acid amplification* .............................................. 12 (4)Drug susceptibilityBACTEC* .......................................................................... 190 (71)Agar proportion................................................................. 31 (12)Both*................................................................................... 45 (17)aMethods recommended by the CDC are indicated with an asterisk. BACTECwas from Becton Dickinson, Sparks, Md. HPLC, high-performance liquid chro-matography; NAP, p-nitro-a-acetylamino-b-hydroxypropiophenone.TABLE 3. Proportion of laboratories using recommended methods for TB testing compared with the proportionof patients tested using recommended methods by laboratory typeTest and groupNo. with recommended method/total no. (%)All laboratoriesLaboratory typePublic health Independent non-HMO HMO HospitalFluorochrome stainingLaboratories 35/44 (80) 3/3 (100) 8/8 (100) 2/2 (100) 22/31 (71)Patients 243/268 (91) 51/54 (94) 39/39 (100) 39/39 (100) 114/136 (84)Liquid culture mediumLaboratories 37/43 (86) 4/4 (100) 8/8 (100) 2/2 (100) 23/29 (79)Patients 248/265 (94) 58/58 (100) 38/38 (100) 39/39 (100) 113/130 (87)Rapid identification of M. tuberculosisaLaboratories 27/27 (100) 5/5 (100) 9/9 (100) 2/2 (100) 11/11 (100)Patients 272/272 (100) 83/83 (100) 61/61 (100) 40/40 (100) 88/88 (100)BACTEC drug susceptibilitiesLaboratories 16/19 (84) 5/6 (83) 6/8 (75) 1/1 (100) 4/4 (100)Patients 235/266 (88) 96/99 (97) 54/82 (66) 23/23 (100) 62/62 (100)a Nucleic acid probe, BACTEC NAP, HPLC, or nucleic acid amplification test.1970 NOTES J. CLIN. MICROBIOL.microscopy and mycobacterial culture should focus on hospitallaboratories. Whereas other laboratories adhered to the use ofrecommended methods for these tests, a large proportion ofhospital laboratories did not use a fluorochrome method forthe initial smear and/or liquid medium for mycobacterial cul-ture.Efforts to further expand the use of recommended methodsfor drug susceptibility testing could focus on independentnon-HMO laboratories. In our study, a lower proportion ofpatients in independent non-HMO laboratories was testedusing BACTEC compared with patients tested in other lab-oratories. In California, the task of improving or monitoringthe adherence to recommended drug susceptibility testingmethods is facilitated by the relatively small number of labo-ratories involved with this type of testing.Study limitations. First, although the sample included 300patients, testing for these patients was performed in a smallnumber of public health, HMO, and independent non-HMOlaboratories. Therefore, our results may not provide an accu-rate portrayal of laboratory testing procedures. For example,assessment of the role of specimen volume in the use of rec-ommended testing methods for smear microscopy and culturein hospital labs was limited by the small number of hospitallaboratories used in the analysis. However, our results do agreewith the results from previous studies showing that hospitallaboratories processing fewer specimens were less likely to userecommended testing methods for smear microscopy and cul-ture (6).Second, data obtained from laboratories that tested a smallnumber of patients may not accurately describe the testingpractices in these laboratories. Some laboratories did not al-ways use the same testing method for all specimens tested inthose laboratories. Therefore, it may not be appropriate toassume a laboratory did or did not comply with recommendedtesting practices based on data from a few patients.Summary. Our findings suggest that most patients undergo-ing evaluation for TB in California are tested using CDC-recommended laboratory methods. These analyses also indi-cate that results based on surveys at the laboratory level maynot accurately reflect results at the patient level. Future effortsto expand the use of recommended methods for smear micros-copy and mycobacterial culture should focus on low-volumehospital laboratories, and for drug susceptibility testing thefocus should be on independent non-HMO laboratories.This work was supported by a cooperative agreement, M2854, fromthe Association of Public Health Laboratories.We thank the members of the Advisory Committee convened by theAssociation of Public Health Laboratories during the design of thisstudy and for their assistance with piloting the study questionnaire. Wealso thank Peter Oh for assistance with data collection and manage-ment, Sarah Royce for critical reading of the manuscript, the fourcounty TB control programs that participated in the study, and all ofthe laboratory personnel who facilitated our access to patient labora-tory records and who completed and returned the questionnaires.REFERENCES1. Bird, B. R., M. M. Denniston, R. E. Huebner, and R. C. Good. 1996. Changingpractices in mycobacteriology: a follow-up survey of state and territorial pub-lic health laboratories. J. Clin. Microbiol. 34:554–559.2. Centers for Disease Control and Prevention. 1992. National action plan tocombat multidrug-resistant tuberculosis. Morb. Mortal. Wkly. Rep. 41(RR-11):1–48.3. Denniston, M. M., B. R. Bird, and K. A. Kelley. 1997. Contrast of surveyresults between state and a cohort of nonstate mycobacteriology laboratories:changes in laboratory practices. J. Clin. Microbiol. 35:422–426.4. Tenover, F. C., J. T. Crawford, R. E. Huebner, L. J. Geiter, C. R. Horsburgh,Jr., and R. C. Good. 1993. The resurgence of tuberculosis: is your laboratoryready? J. Clin. Microbiol. 31:767–770.5. Tokars, J. I., J. R. Rudnick, K. Kroc, L. Manangan, G. Pugliese, R. E.Huebner, J. Chan, and W. R. Jarvis. 1996. U.S. hospital mycobacteriologylaboratories: status and comparison with state public health department lab-oratories. J. Clin. Microbiol. 34:680–685.6. Woods, G. L., T. A. Long, and F. G. Witebsky. 1996. Mycobacterial testing inclinical laboratories that participate in the College of American Pathologistsmycobacteriology surveys. Arch. Pathol. Lab. Med. 120:429–435.TABLE 4. Comparison of hospital laboratories using or not usingrecommended testing methods for smear microscopy andculture, by average monthly volume of specimensprocessed for TB testingUse of recommendedmethod(s)Totalno.No. of labs (%) withmonthly vol ofspecimensx2 fortrend (p)0–50 51–100 .100Use of fluorochrome stainingfor smear microscopyYes 17 4 (24) 5 (29) 8 (47) 1.73 (0.19)No 9 4 (44) 3 (33) 2 (22)Use of liquid culturemediumYes 18 4 (22) 5 (28) 9 (50) 2.33 (0.13)No 6 3 (50) 2 (33) 1 (17)VOL. 39, 2001 NOTES 1971

Use of Recommended Laboratory Testing Methods Among Patients with Tuberculosis in California

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Use of Recommended Laboratory Testing Methods Among Patients with Tuberculosis in California

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