Reflex Testing

Jump To:

Introduction

Diagnostic Laboratory Services offers medically necessary reflex testing to facilitate effective and efficient patient care while remaining compliant with state and federal regulations governing the ordering of laboratory tests.

Reflexed tests are any test that automatically results in the order of one or more secondary tests based on preset criteria applied to the initial test. The secondary tests are almost always an additional charge above the initial test. When ordering a reflexed test, you must consider whether the secondary tests are medically necessary for the specific patient and for the specific situation in which the order is placed. If you consider the secondary tests unnecessary, order the initial test without the reflex.

Certain reflex testing has been predetermined based on specific criteria accepted as standard-of-care by the medical community. These tests will always reflex because the initial test result is not useful without the reflex test result and, therefore, individual components may not be available for ordering.

Note: The reflex test list provided below includes only tests performed by DLS. For tests that are referred out, please see each reference laboratory’s website for details.

General Laboratory Reflex Testing

Order Code Test Name
59R VDRL, CSF
If VDRL is reactive, sent to Hawaii Department of Health for confirmation.
142R Cholesterol, Reflex to Lipid Profile
If Cholesterol is >200 mg/dL, Lipid Profile is performed.
314R Prolactin, w/ Reflex to Monomeric
Male: If Prolactin is > 15.2 ng/mL, Monomeric Prolactin is performed.
Female: If Prolactin is > 23.3 ng/mL, Monomeric Prolactin is performed.
380R TSH, w/ Reflex to Free T4
1 Day: If TSH is <9.20 or >28.40 uIU/mL, Free T4 is performed
2 Days: If TSH is <6.60 or >15.60 uIU/mL, Free T4 is performed
3 Days: If TSH is <0.83 or >8.65 uIU/mL, Free T4 is performed
4 Days to <2 Months: If TSH is <0.67 or >5.57 uIU/mL, Free T4 is performed
Adult (≥ 2 Months): If TSH is <0.27 or >4.20 uIU/mL, Free T4 is performed.
450R HCG, Qual., Reflex to Quant.
If hCG is positive, Quantitiative hCG is performed.
502R Hepatitis A Antiody, Reflex to IgM
If total HAV Ab is positive, HAV IgM is performed.
505R PSA, Screen, w/ Reflex to Free PSA
If Total PSA is 2.5 to 10.0 ng/mL, Free PSA is performed.
505RD PSA, Diagnostic, w/ Reflex to Free PSA
If Total PSA is 2.5 to 10.0 ng/mL, Free PSA is performed.
542R HCV Antibody w/ Reflex to RNA Quantitative & Genotype
If HCV is reactive, HCV Quant w/ Reflex to Genotype is performed.
636R UA, w/o Micro, w/ Reflex to Albumin, UR
If urine protein is negative, quantitative Urine Albumin is performed.
637R UA, Micro Only w/ Reflex to C&S
If the microscopic shows WBC >5/hpf and/or bacteria >moderate, Urine Culture is performed.
652 UA, Complete, w/ Reflex to C&S
If dipstick is positive for leukocyte and/or nitrites or the microscopic shows WBC >5/hpf and/or bacteria >moderate, Urine Culture is performed.
695R RPR, Reflex to Titer
If RPR is reactive, Titer is performed and sent to DOH for confirmation.
915R Lipid Profile w/ Reflex LDL-D
If Triglycerides are >400 mg/dL, Direct LDL is performed.
4983R Cryptococcus Ag, CSF, Rflx Culture
If CSF Cryptococcus Antigen testing is positive, Fungus Culture is performed.
6731 CK-Total, Reflex to Troponin T
Male: If Total CK is >308 IU/L, Troponin T is performed.
Female: If Total CK is >192 IU/L, Troponin T is performed.
6853R Milk, IgE, Reflex Component Panel
If Milk Specific IgE is greater than or equal to 0.1 kU/L, Milk Component Panel is performed.
6866R Peanut, IgE, Reflex Component Panel
If Peanut Specific IgE is greater than or equal to 0.1 kU/L, Peanut Component Panel is performed.
6898R Egg White, IgE, Reflex Comp. Panel
If Egg White Specific IgE is greater than or equal to 0.1 kU/L, Egg Component Panel is performed.
7055R HCV Antibody w/ Reflex to HCV RNA Quantitative
If HCV Antibody is positive, HCV RNA Quant is performed.
7760 HIV-1/2 Ag/Ab with Reflex
If HIV 1/2 Ag/Ab is positive, Geenius HIV 1/2 Supplemental assay is performed.

Blood Bank and Coagulation Reflex Testing

Order Code Test Name
13 Blood Group and Rh
If there is a discrepancy in Blood Group and/or Rh type, the discrepancy will be investigated. Additional tests may include Antibody Screen and Direct Antiglobulin Test. See below for reflex testing if these additional tests are positive.
14 Antibody Screen
If Antibody Screen is positive, Antibody Identification (ID) is performed. Additional tests may include:

  • Antibody Identification
  • Antibody ID (Absorption)
  • Antibody ID (Inhibition)
  • Antibody ID (Enzyme)
  • Antibody ID (Special – Reference lab)
  • RBC Antigens (1AG – 8AG)
  • Rh Phenotype, Complete
  • Direct Antiglobulin Test (IgG and C3)
  • Antibody Titer
18 Direct Antiglobulin Test (IgG and C3)
A positive Direct Antiglobulin Test will be further characterized to determine if it is IgG, complement or both. Additional tests may include Direct Antiglobulin Test (IgG), Direct Antiglobulin Test (C3), Antibody ID (Elution).
5486 Coagulation Mixing Study

  • If no PT/PTT ordered, PT/PTT is performed.
  • If only PTT ordered, PT is performed.
  • If only PT ordered, PTT is performed.
  • If PT is abnormal, PT mix, incubated PT and incubated PT mix is performed.
  • If PTT is abnormal, PTT mix, incubated PTT and incubated PTT mix is performed.
  • If PTT is abnormal, Thrombin Time is performed.
  • If Thrombin Time is abnormal, Fibrinogen is performed.
6674 Lupus Anticoagulant DRVVT

  • If no PT/PTT ordered, PT/PTT is performed.
  • If only PTT ordered, PT is performed.
  • If only PT ordered, PTT is performed.
  • If DRVV Screen Ratio is abnormal, DRVV Confirm Ratio is performed.
  • If DRVV Screen Ratio is abnormal, DRVVT Mix is performed.
  • If DRVV Screen Ratio is abnormal, Thrombin Time is performed.
  • If PTT is abnormal, Thrombin Time is performed.

Microbiology Reflex Testing

Order Code Test Name
93 Lower Resp Tract Culture w/ Gram Stain

  • If growth present, pathogens are identified and sensitivities done on each pathogen. All IDs and sensitivities are charged; workups limited to six isolates.
  • ID test code per isolate.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
308 Vibrio Stool Culture

  • If growth suspicious for Vibrio is present, identification is done and charged if growth is identified as Vibrio sp.
  • ID test code per isolate.
311 Yersinia Stool Culture

  • If growth suspicious for Yersinia is present, identification is done and charged if growth is identified as Yersinia sp.
  • ID test code per isolate.
617 Throat Culture

  • If growth suspicious for Staphylococcus aureus is present, identification is done and charged if
    growth is identified as Methicillin Resistant Staph aureus.
  • ID test code per isolate.
618 MRSA Culture Screen

  • If growth suspicious for Staphylococcus aureus is present, identification is done and charged if growth is identified as Methicillin Resistant Staph aureus.
  • ID test code per isolate.
619 Blood Culture

  • All growth is identified and charged. Sensitivities are charged on all growth for which susceptibility testing standards are available.
  • ID test code per isolate.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
620 CSF Culture & Gram Stain

  • All growth is identified and charged. Sensitivities are charged on all growth for which susceptibility testing standards are available.
  • ID test code per isolate.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
621 Anaerobic Culture

  • If growth present, identifications are done and charged on all anaerobic isolates.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
  • ID test code per isolate.
622 Stool Culture w/ Shiga Toxin

  • If growth suspicious for Salmonella, Shigella, Campylobacter, E.coli 0157, Aeromonas, or Plesiomonas is present, identification is done and charged if growth is identified as a stool pathogen.
  • ID test code per isolate.
624 Miscellaneous Culture

  • If growth present, identifications are done and charged according to source type. Sensitivities are done and charged on pathogens. (Work-ups limited to three isolates.)
  • ID test code per isolate.
  • ID test code per anaerobic isolate.
  • If unable to identify isolate and from a critical source, identification by 16S rRNA sequencing is performed.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
625 GC Screen

  • If growth suspicious for GC is present, identification is done and charged if growth is identified as GC.
  • ID test code per isolate.
626 Urine Culture

  • If growth present, identifications are done on predominant and/or significant organisms and sensitivities are also done if these organisms are pathogens. All IDs and sensitivities are charged.
  • ID test code per isolate.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
626C Cath Urine Culture

  • If growth present, identifications are done on predominant and/or significant organisms and sensitivities are also done if these organisms are pathogens. All IDs and sensitivities are charged.
  • ID test code per isolate.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
644 Body Fluid Culture and Gram Stain

  • If growth present, identifications are done on predominant and/or significant organisms and sensitivities are also done if these organisms are pathogens. All IDs and sensitivities are charged.
  • ID test code per isolate.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
645 Fungus Culture, (Not Hair, Skin or Nail)

  • If growth is isolated, identifications are performed on any mold or yeast present. All IDs are charged.
  • ID test code per isolate, yeast.
  • ID test code per isolate, mold.
  • Dimorphic fungi (e.g. C. immitis, Blastomyces, Histoplasma) to be reflexed to a DNA Probe Test to be performed by a reference lab.
646 AFB Blood/Bone Marrow
If growth is isolated, further testing is done as follows:

  • TB DNA probe is done.
  • If TB DNA probe is positive, TB sensitivity is done. NOTE: sensitivity is charged for each drug tested.
  • If TB sensitivity is resistant to 1 drug:
    • Isolate is referred to reference lab for single drug MIC testing.
    • If drug is Rifampin, isolate is referred to reference lab for secondary drug panel.
    • If drug is PZA, isolate is referred to reference lab for Mycobacterial MIC testing.
  • If TB sensitivity is resistant to 2 or more drugs:
    • Isolate is referred to reference lab for primary drug panel.
    • If isolate is resistant to Rifampin, isolate is also referred for a secondary drug panel.
  • If TB DNA probe is negative, MALDI-TOF identification is done and charged.
  • If identification by MALDI-TOF is acceptable, sample referred to reference lab for sensitivity testing.
  • If identification by MALDI-TOF is unacceptable, sample referred to reference lab for further ID/sensitivity testing.
651 Acid Fast Smear and Culture
If growth is isolated, further testing done as follows:

  • TB DNA probe is done.
  • If TB DNA probe is positive, TB sensitivity is done. NOTE: sensitivity is charged for each drug tested.
  • If TB sensitivity is resistant to 1 drug:
    • Isolate is referred to reference lab for single drug MIC testing.
    • If drug is Rifampin, isolate is referred to reference lab for secondary drug panel.
    • If drug is PZA, isolate is referred to reference lab for Mycobacterial MIC testing.
  • If TB sensitivity is resistant to 2 or more drugs:
    • Isolate is referred to reference lab for primary drug panel.
    • If isolate is resistant to Rifampin, isolate is also referred for a secondary drug panel.
  • If TB DNA probe is negative, MALDI-TOF identification is done and charged.
  • If identification by MALDI-TOF is acceptable, sample referred to reference lab for sensitivity testing.
  • If identification by MALDI-TOF is unacceptable, sample referred to reference lab for further ID/sensitivity testing.
661 VRE Culture Screen

  • If growth suspicious for Enterococcus is present, identification is done and charged if growth is identified as Vancomycin Resistant Enterococcus.
  • ID test code per isolate.
4105 Bone Marrow Culture

  • All growth is identified and charged. Sensitivities are charged on all growth for which susceptibility testing standards are available.
  • ID test code per isolate.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
4106 Catheter Tip Culture

  • If growth present, identifications are done and charged on all isolates. Sensitivities are done and charged on all pathogens and non-pathogens showing a significant colony count; workups limited to six isolates.
  • ID test code per isolate.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
4533 Organism ID – Fungal

  • All fungal isolates are identified and charged. Culture itself is not charged as these are submitted as pre-cultured specimens, but a handling fee will be assessed if mixed isolates are received
  • ID test code per isolate, yeast.
  • ID test code per isolate, mold.
  • Dimorphic fungi (e.g. C. immitis, Blastomyces, Histoplasma) to be sent to a reference lab for confirmatory testing and identification.
4534 Organism ID – AFB

  • All mycobacterial isolates are identified and charged. Culture itself is not charged as these are submitted as pre-cultured specimens, but a handling fee will be assessed if mixed isolates are received.
  • If growth is isolated, further testing is done as follows:
  • TB DNA probe is done.
  • If TB DNA probe is positive, TB sensitivity is done. NOTE: sensitivity is charged for each drug tested.
  • If TB sensitivity is resistant to 1 drug:
    • Isolate is referred to reference lab for single drug MIC testing.
    • If drug is Rifampin, isolate is referred to reference lab for secondary drug panel.
    • If drug is PZA, isolate is referred to reference lab for Mycobacterial MIC testing.
  • If TB sensitivity is resistant to 2 or more drugs:
    • Isolate is referred to reference lab for primary drug panel.
    • If isolate is resistant to Rifampin, isolate is also referred for a secondary drug panel.
  • If TB DNA probe is negative, MALDI-TOF identification is done and charged.
  • If identification by MALDI-TOF is acceptable, sample referred to reference lab for sensitivity testing.
  • If identification by MALDI-TOF is unacceptable, sample referred to reference lab for further ID/sensitivity testing.
4535 Organism ID – Anaerobic

  • All anaerobic isolates are identified and charged. Culture itself is not charged as these are submitted as pre-cultured specimens, but a handling fee will be assessed if mixed isolates are received.
  • ID test code per isolate.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
5512 Genital Culture

  • If growth present, identifications are done and charged according to source type. Sensitivities are done and charged on pathogens in significant numbers. (Work-ups limited to three isolates.)
  • ID test code per isolate.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
5519 Abscess Culture

  • If growth present, identifications are done and charged according to source type. Sensitivities are done and charged on pathogens. (Work-ups limited to three isolates.)
  • ID test code per isolate.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
5521 Aspirate Culture

  • If growth present, identifications are done and charged according to source type. Sensitivities are done and charged on pathogens. (Work-ups limited to three isolates.)
  • ID test code per isolate.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
5535 Wound Culture

    • If growth present, identifications are done and charged according to source type. Sensitivities are done and charged on pathogens. (Work-ups limited to three isolates.)
    • ID test code per isolate.
    • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
    • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
    • Sensitivity test code per isolate (dependent on method used):
      • Agar Dilution method
      • Disk method
      • Microtiter MIC method
5783 Tissue Culture with Gram Stain

  • If growth present, identifications are done and charged according to source type.  Sensitivities are done and charged on pathogens.
  • ID test code per isolate.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
5823 Prostatitis Culture

  • If growth present, identifications are done on all organisms with colony counts >1,000 organisms/mL and sensitivities are also done if these organisms are pathogens. All IDs and sensitivities are charged.
  • ID test code per isolate.
  • If unable to identify isolate, identification by 16S rRNA sequencing may be performed.
  • If isolate identified as Staph aureus, and patient is an inpatient, an “MRSA, Rapid Test” may be done (dependent on sufficient growth).
  • Sensitivity test code per isolate (dependent on method used):
    • Agar Dilution method
    • Disk method
    • Microtiter MIC method
6204R GBS Screen, DNA NAAT w/ Reflex Sensi

  • Positive results will reflex to a no charge culture for isolation of GBS for susceptibility testing by Microtiter MIC method.
6233 Fungus Culture, Hair/Nail/Skin

  • If growth is isolated, identifications are performed on any mold or yeast present. All IDs are charged.
  • ID test code per isolate, yeast.
  • ID test code per isolate, mold.
  • Dimorphic fungi (e.g. Cimmities, Blastomyces, Histoplasma) to be reflexed to a DNA Probe Test to be performed by a reference lab.
N/A Unusually resistant or atypical sensitivity patterns

  • Supplemental testing may be performed; test code dependent on method used.
    • Agar Dilution method
    • Microtiter MIC method
    • Referral to a Reference Laboratory for Broth Dilution or confirmatory testing.
  • Resistant inpatient Pseudomonas aeruginosa will reflex to Carbapenemase testing based on:
    • Resistance to imipenem AND
    • Resistance to extended spectrum cephalosporins AND
    • Non-susceptible to meropenem screen test
N/A Unusual or difficult identifications

  • Supplemental testing may be performed; test code dependent on method used.
    • Bacterial ID by DNA Sequencing.
    • Referral to a Reference Laboratory; dependent on whether isolate is a bacteria, yeast, mold or AFB.

Molecular Reflex Testing

Order Code Test Name
5442R HCV Quant w/ Reflex to Genotype
If HCV viral load is >=300 IU/mL, HCV Genotyping is performed.
5509R HBV Quant w/ Reflex to Genotype
If HBV viral load is >=600 IU/mL, HBV Genotyping is performed.
7123 C. difficile GDH/Toxin w/ Reflex to NAAT
Discordant antigen / toxin results will reflex to Nucleic Acid Amplification Testing.
Revised: 1/2023