Choice A reason:

The standard recommendation for fasting before a blood specimen collection is typically between 8 to 12 hours¹²³. This duration is considered sufficient to ensure that food intake does not affect the blood test results, such as glucose or lipid levels.

Choice B reason:

A fasting period of 1 to 2 hours is too short and would not provide an accurate representation of the body's baseline levels for most tests that require fasting. It is important for certain levels, like blood sugar and lipids, to stabilize, which takes longer than 1 to 2 hours.

Choice C reason:

Fasting for 4 to 6 hours may be appropriate for some tests, but it is not the standard fasting duration for most blood tests that require fasting. The shorter time might not allow for the clearance of lipids and glucose from the bloodstream that can influence the test outcomes.

Choice D reason:

A 24-hour fast is generally not required for routine fasting blood tests and could be potentially harmful, as it may lead to hypoglycemia, especially in diabetic patients or those with metabolic disorders. It is excessive for the purposes of standard blood tests.

Choice A Reason:

SST, or Serum Separator Tube, contains a gel at the bottom to separate the blood from the serum upon centrifugation. It does not indicate plasma; rather, it is used to collect serum after the blood has clotted. The SST allows for the blood to clot and the serum to be separated for various tests that require serum instead of plasma.

Choice B Reason:

Sodium fluoride is a common additive in collection tubes that serves as a glycolysis inhibitor. It preserves glucose levels and is not specifically indicative of serum. However, it is often used in grey-top tubes, which are typically used for glucose testing and may contain plasma, not serum.

Choice C Reason:

Sodium citrate is an anticoagulant that binds calcium in the blood, preventing clotting. Tubes with sodium citrate are used to collect plasma for coagulation studies, not serum. Therefore, this statement is incorrect as sodium citrate indicates plasma, not serum.

Choice D Reason:

EDTA, or Ethylenediaminetetraacetic acid, is an anticoagulant that binds calcium ions, preventing blood from clotting. Tubes with EDTA are used for collecting plasma because they prevent clotting and allow for the separation of plasma from the blood cells upon centrifugation. This is the correct choice as EDTA indicates plasma.

Choice A Reason:

Signing a release for laboratory results is a form of expressed consent, not implied consent. Expressed consent is given explicitly, either orally or in writing, and is clearly and unmistakably communicated. It involves a clear action of agreement to the specific procedure or intervention proposed.

Choice B Reason:

Signing a document of agreement for a research study is also an example of expressed consent. The patient is actively agreeing to participate in the study, which is a direct and informed action. This type of consent is necessary for research studies to ensure that participants are fully aware of the study's nature and any potential risks involved.

Choice C Reason:

Implied consent occurs when a patient's actions suggest consent without verbal or written confirmation. Offering an arm to a phlebotomist is a non-verbal communication that implies the patient is willing to have their blood drawn. This is a common practice in medical settings where the action of presenting an arm indicates readiness for the procedure.

Choice D Reason:

A family member nodding for a phlebotomist to proceed does not constitute the patient's implied consent. Consent must come directly from the patient unless they are unable to provide it, in which case a legal surrogate may give consent on their behalf. The nod of a family member cannot be assumed as the patient's consent.

Choice A Reason:

Using only one patient identifier is not sufficient to ensure patient safety and accuracy in healthcare settings. It increases the risk of misidentification, which can lead to serious medical errors. Therefore, one identifier is not the standard practice for patient verification before a blood draw.

Choice B Reason:

While two identifiers are commonly used in many healthcare settings as a minimum requirement, they may not always provide enough differentiation, especially in larger facilities where patient names may be similar. Two identifiers are often the minimum standard, but they are not the most comprehensive approach.

Choice C Reason:

Three unique patient identifiers provide a more robust method for verifying a patient's identity, significantly reducing the likelihood of errors. According to the Clinical and Laboratory Standards Institute (CLSI), three identifiers are recommended to ensure the correct patient is being collected. This may include the patient's full name, date of birth, and medical record number or another unique identifier.

Choice D Reason:

While using four unique identifiers could further reduce the risk of patient misidentification, it is not typically required as the standard minimum. Three identifiers are generally considered adequate for most healthcare settings to ensure patient safety and proper identification.

Choice A Reason:

While informing the patient of the procedure is important, it is not the immediate next step after greeting. The technician should first ensure the patient's safety and comfort before proceeding with the details of the blood draw.

Choice B Reason:

Asking if the patient has a latex allergy is crucial as it directly pertains to patient safety. Many medical supplies, including gloves and tourniquets used during phlebotomy, may contain latex, which can cause allergic reactions in sensitive individuals. Identifying an allergy before any contact ensures that the technician can take necessary precautions to prevent an allergic reaction.

Choice C Reason:

Stating the technician's name to the patient helps build rapport but is not as critical as ensuring the patient's safety. It is a part of good communication and patient care practices but should follow after confirming any potential allergies or other immediate health concerns.

Choice D Reason:

Asking the patient which arm they prefer for the blood draw is a part of the procedure that involves patient preference and comfort. However, this should come after ensuring there are no allergies that could lead to complications during the draw.

Choice A Reason:

Shoe covers are used to protect the shoes and prevent the spread of contaminants from one area to another. They are not specifically required for droplet precautions during blood glucose monitoring. Droplet precautions typically focus on protecting mucous membranes of the eyes, nose, and mouth from droplet spatter.

Choice B Reason:

Masks are essential when dealing with patients under droplet precautions. Droplets can transmit infections when a person coughs, sneezes, or talks, and a mask provides a barrier that prevents the inhalation of these potentially infectious droplets. For procedures like blood glucose monitoring, where close contact with the patient is necessary, wearing a mask is crucial to protect both the healthcare worker and the patient.

Choice C Reason:

A gown is used to protect the healthcare worker's skin and clothing from contamination with potentially infectious material. While it is an important piece of personal protective equipment, it is not the primary requirement for droplet precautions in the context of blood glucose monitoring, unless there is a risk of substantial splashing or spraying of bodily fluids.

Choice D Reason:

Goggles are used to protect the eyes from splashes of blood or other body fluids. They are important in procedures where there is a risk of splashing, but for blood glucose monitoring, the risk is minimal. Therefore, goggles are not the primary piece of equipment required for droplet precautions in this scenario.

Choice A Reason:

Positioning the needle at a 45° angle to the skin is not the recommended approach for venipuncture using a butterfly needle on dorsal hand veins. The correct angle for insertion is usually less than 45°, often around 15-30°, to ensure a shallow entry and reduce the risk of going through the vein.

Choice B Reason:

Holding the needle by the wings of the butterfly is the correct technique. This allows for better control and stability during insertion. The wings are designed to be held between the thumb and forefinger, providing an easy grip for the phlebotomist to maneuver the needle with precision.

Choice C Reason:

Instructing the patient to hold the collection tubes is not standard practice and could lead to pre-analytical errors. The phlebotomist should maintain control of the tubes to ensure proper blood flow and fill volume, as well as to prevent contamination or accidents.

Choice D Reason:

Applying the tourniquet at the antecubital area is not specific to the use of a butterfly needle for venipuncture on dorsal hand veins. While a tourniquet is used to engorge the veins and make them more prominent, its placement may vary depending on the selected puncture site and is not the action in question here.

Choice A Reason:

Explaining the procedure to both the parent and the child is crucial. It helps in preparing the child psychologically and ensures that the parent is informed and can provide support during the process. Clear communication can reduce anxiety and make the child more cooperative. It is also a part of informed consent, where the parent understands what the procedure entails and why it is necessary¹².

Choice B Reason:

Choosing not to tell the child when the needle insertion is coming might seem like a way to avoid causing them anticipatory anxiety. However, this approach can lead to mistrust. Children need to be prepared for what to expect, and surprising them can be more traumatic in the long run. It is better to be honest and use age-appropriate language to describe the sensation as a 'quick pinch' or 'poke'¹².

Choice C Reason:

Obtaining a heel stick is a common method for blood collection in infants, particularly newborns, as their veins are not as developed. However, for preschoolers, venipuncture is usually the preferred method because they have more developed veins, and it allows for a larger volume of blood to be collected if needed³.

Choice D Reason:

Obtaining a thumb stick is not a standard practice for blood collection in preschoolers. The thumb has bones and tendons close to the surface, which can increase the risk of injury. The preferred sites are the antecubital fossa of the arm or the back of the hand where the veins are more accessible and there is less risk of hitting bone³.

Choice A Reason:

The chain of custody form is crucial in the context of a toxicology drug screen for legal purposes. It is a document that records the sequence of custody, control, transfer, analysis, and disposition of physical and electronic evidence. It is particularly important in legal cases where the results of the toxicology screen can be used as evidence in court. The chain of custody ensures that the sample has been handled properly and that the integrity of the sample has been maintained throughout the testing process.

Choice B Reason:

A requisition form is used to request a specific test or service. While it is an essential document in the process of ordering a toxicology drug screen, it does not serve the same purpose as the chain of custody in terms of legal proceedings. The requisition form typically includes patient information, the tests ordered, and the reason for the test, but it does not track the handling of the sample.

Choice C Reason:

An encounter form, also known as a superbill, is used in medical billing to capture the services provided during a patient's visit. It includes information about the patient's diagnosis, the procedures performed, and the codes for billing purposes. However, it is not specifically related to the legal aspects of a toxicology drug screen.

Choice D Reason:

The CMS 1500 form is the standard claim form used by healthcare providers to bill Medicare and Medicaid services. It is also used by some private insurers and managed care plans. Like the encounter form, it is related to billing and not to the legal chain of custody required for a toxicology drug screen.

Choice A Reason:

Assault is an act that threatens physical harm to a person, whether or not actual harm is done. It is an intentional act where the assailant engages in an action that makes the victim fear an imminent harmful or offensive contact. It does not necessarily involve actual physical contact.

Choice B Reason:

Battery is the intentional and wrongful physical contact with a person without their consent that results in some injury or offensive touching. Unlike negligence, battery requires intentional conduct that results in harmful or offensive contact with another person.

Choice C Reason:

Negligence is the failure to take proper care in doing something, which leads to damage or injury to another person. It involves a breach of duty of care that results in harm. Negligence is not intentional; it is a legal concept that implies that a reasonable level of care was not met under the circumstances.

Choice D Reason:

Fraud is a deliberate deception to secure unfair or unlawful gain, or to deprive a victim of a legal right. Fraud involves intentional misrepresentation or concealment of an important fact upon which the victim is meant to rely, and does so to the victim's detriment. This is different from negligence, which does not involve intentional deceit.

Choice A Reason:

Encouraging the patient to chew gum during the procedure may serve as a distraction, which can be helpful for some patients. However, this is not a widely recommended practice for reducing needle phobia. Distraction techniques can be beneficial, but they should be tailored to the individual patient's preferences and should not interfere with the procedure.

Choice B Reason:

Instructing the patient to lie supine during the procedure can help prevent fainting and reduce anxiety for some patients. This position is often used for patients who have a history of fainting or feel dizzy during blood draws. However, it is not specifically targeted at managing needle phobia.

Choice C Reason:

Placing the patient's elbow joint at 90 degrees of flexion is a standard practice to stabilize the arm and provide an optimal angle for venipuncture. While this is a necessary step in the procedure, it does not directly address the patient's needle phobia.

Choice D Reason:

Warming the site for 10 minutes before venipuncture is a technique used to enhance vein visibility and elasticity, making the venipuncture easier and potentially less painful. This can be particularly helpful for patients with needle phobia, as a smoother and quicker procedure may reduce anxiety and discomfort.

Choice A Reason:

The right antecubital fossa is not the optimal site for blood collection in this case because the presence of a shunt in the right forearm can complicate the procedure and potentially damage the shunt, which is a critical access point for dialysis treatments.

Choice B Reason:

The right hand should also be avoided for blood collection due to the shunt placement in the right forearm. Using the same arm as the shunt for venipuncture could lead to complications such as infection, clotting, or accidental damage to the shunt.

Choice C Reason:

The left antecubital fossa might seem like a viable option; however, with an IV placed in the left hand, it is generally recommended to avoid using the same limb for blood collection to prevent contamination of the sample and reduce the risk of infection at the IV site.

Choice D Reason:

Capillary collection from the left hand is the most appropriate choice in this scenario. It avoids the arm with the shunt and the IV, reducing the risk of complications. Capillary blood collection is a suitable alternative when venipuncture sites are limited, and it can provide an adequate sample for a CBC.

Choice A Reason:

A patient's room number is not considered a unique identifier by the Joint Commission standards. Room numbers can change if patients are moved, and they do not reliably identify an individual.

Choice B Reason:

A patient's bed label is also not a unique identifier. Bed labels can be switched, and similar to room numbers, they are not specific to the individual patient.

Choice C Reason:

A patient's inpatient chart typically contains multiple unique identifiers, such as the patient's name, an assigned identification number, date of birth, or other person-specific identifiers. These are considered acceptable by the Joint Commission for verifying patient identity, ensuring that the service or treatment is intended for that individual.

Choice D Reason:

Patient's verbal confirmation alone is not sufficient for establishing correct inpatient identification. While it can be used as one method of identification, it should be supplemented with another identifier to meet the Joint Commission's requirement of using at least two patient identifiers.

Choice A Reason:

Standard precautions are a set of infection control practices used to prevent transmission of diseases that can be acquired by contact with blood, body fluids, non-intact skin (including rashes), and mucous membranes. These measures are to be applied to all patients, regardless of their diagnosis or presumed infection status. Standard precautions include hand hygiene, use of personal protective equipment (PPE), respiratory hygiene/cough etiquette, safe injection practices, safe handling of potentially contaminated equipment or surfaces in the patient environment, and aseptic technique.

Choice B Reason:

Safety devices, such as needles with engineered sharps injury protections, are designed to prevent needlestick injuries and the transmission of bloodborne pathogens. While they are an important aspect of a phlebotomist's work, they are not specifically part of the aseptic technique protocol. Aseptic technique focuses on preventing contamination of sterile surfaces and materials to prevent infection.

Choice C Reason:

Quality control logs are records that document the performance of equipment and procedures to ensure they meet the required standards. They are essential for maintaining the integrity of laboratory results and ensuring patient safety. However, quality control logs themselves are not a component of the aseptic technique protocol, which is more concerned with the immediate prevention of infection during clinical procedures.

Choice D Reason:

A disaster emergency plan is a comprehensive document outlining the actions to be taken in case of an emergency. This plan is crucial for ensuring safety and continuity of care during unexpected events but is not related to the aseptic technique protocol. Aseptic technique is a method used to prevent infection during medical procedures by maintaining a sterile environment.

Choice A Reason:

Povidone-iodine is an antiseptic used for skin disinfection before and after surgery. It has a broad spectrum of antimicrobial activity, but it is not the preferred choice for capillary blood collection due to the potential interference with certain laboratory tests. Povidone-iodine needs to be completely dried to avoid hemolysis of the sample, which can affect test results.

Choice B Reason:

Hand sanitizer is generally used for hand hygiene and not for the disinfection of the site for blood specimen collection. While it is effective in killing germs on the skin, it contains emollients and gelling agents that can contaminate the blood sample and interfere with laboratory tests.

Choice C Reason:

70% isopropyl alcohol is the most commonly used disinfectant for aseptic technique in capillary blood collection. It is effective against a broad range of microorganisms and evaporates quickly, leaving no residue that could contaminate the sample. It is important to allow the alcohol to dry completely before performing the puncture to prevent stinging and sample dilution.

Choice D Reason:

A 10% chlorine bleach solution is not typically used for skin disinfection in blood collection due to its harshness and potential to cause skin irritation and damage. It is more commonly used for disinfecting surfaces and equipment in healthcare settings.

Choice A Reason:

Withdrawing the needle completely would be an incorrect action because it would end the procedure prematurely and require a new venipuncture, causing unnecessary discomfort to the patient. It should only be done if the venipuncture has been completed or if there is a need to stop due to a complication.

Choice B Reason:

Rotating the bevel of the needle could potentially reposition the needle for better blood flow if it has become occluded or is not properly aligned with the vein. However, this action should be done with caution to avoid causing injury to the vein or discomfort to the patient.

Choice C Reason:

Increasing tourniquet pressure is not advisable once blood flow has been established, as it could cause damage to the vein or hemolysis of the blood sample. The tourniquet should be released once the blood starts flowing into the first tube to avoid these issues.

Choice D Reason:

Activating a new evacuated tube is the correct action to take when blood flow stops upon attaching a second tube. This could indicate a problem with the vacuum in the tube rather than with the needle or the venipuncture site. Trying a new tube can resolve the issue without needing to adjust the needle or the patient's position.

Choice A Reason:

Anchoring a vein is a technique used to stabilize the vein during venipuncture to prevent it from rolling. The recommended practice is to anchor the vein 1 to 2 inches below the puncture site. This is done by applying gentle traction on the skin downward with the thumb, which helps to stabilize the vein and facilitate the insertion of the needle.

Choice B Reason:

Anchoring 1 to 2 inches above the puncture site is not the standard practice. This position would not provide the necessary tension on the vein to prevent it from rolling and could make the venipuncture more difficult.

Choice C Reason:

Anchoring 2 inches left of the puncture site does not provide the correct angle or tension for stabilizing the vein for a venipuncture and is not a recommended technique.

Choice D Reason:

Anchoring 1 inch right of the puncture site is also not a recommended practice. Similar to anchoring to the left, this does not provide the proper stabilization needed for a successful venipuncture.

Choice A Reason:

Reporting the needlestick to the supervisor is an important step in the post-exposure protocol, but it is not the first action that should be taken. The immediate priority is to address the potential exposure to pathogens by cleansing the wound.

Choice B Reason:

Completing the blood draw is not the appropriate first action after a needlestick injury. The phlebotomist's health and safety take precedence, and the procedure should be paused to address the injury.

Choice C Reason:

Washing the area with soap and water is the first and most critical action to take after an accidental needlestick. This helps to remove any blood or pathogens that may have been introduced to the wound site. It is essential to do this immediately to reduce the risk of infection.

Choice D Reason:

Seeking immediate treatment is a necessary step, but it follows the initial cleansing of the wound. After washing the area, the phlebotomist should then report the incident and seek medical advice to assess the need for further treatment, such as post-exposure prophylaxis.

Choice A Reason:

Prepping the site with povidone iodine is not typically associated with hemoconcentration. Povidone iodine is used as an antiseptic to clean the skin before venipuncture to prevent infection. While it's important to allow it to dry to avoid sample contamination, it does not cause hemoconcentration.

Choice B Reason:

Leaving the tourniquet in place for more than 2 minutes can lead to hemoconcentration. A tourniquet is applied to engorge the veins, making them easier to puncture. However, prolonged application can result in fluid being forced out of the vein into the tissue, increasing the concentration of cells and larger molecules in the blood. This can affect certain laboratory test results by artificially increasing the levels of cellular components.

Choice C Reason:

Not refrigerating the specimen within 30 minutes does not cause hemoconcentration. However, it can affect the stability of certain analytes in the blood sample. Refrigeration is necessary for preserving the integrity of certain components of the blood until analysis, but it is unrelated to the concentration of cells within the sample at the time of collection.

Choice D Reason:

Removing the needle before the tourniquet is released does not cause hemoconcentration. This action might lead to other complications, such as hematoma formation, but it does not affect the concentration of cellular elements in the collected sample.

Choice A Reason:

A quiet and professional tone of voice is essential for a phlebotomy technician when introducing themselves to a patient. This tone conveys respect and maintains a calm environment, which is particularly important in healthcare settings where patients may be anxious or fearful about medical procedures. A professional demeanor helps to establish trust and reassures the patient that they are in capable hands.

Choice B Reason:

A loud and authoritative tone is not appropriate when introducing oneself to a patient. It can be intimidating and may increase the patient's anxiety. The goal is to make the patient feel comfortable and safe, not overpowered or coerced.

Choice C Reason:

Being assertive and humorous can sometimes help to lighten the mood and make the patient feel more at ease. However, humor must be used judiciously as it may not be well-received by all patients, especially in a medical setting where they might be experiencing stress or discomfort.

Choice D Reason:

A commanding and confident tone may convey confidence, but it can also come across as overbearing. While confidence is important, it should not overshadow the need for empathy and understanding of the patient's feelings and comfort.

Choice A Reason:

The median cubital vein is often the first choice for venipuncture due to its size and accessibility. It is located in the antecubital fossa and is usually well anchored by surrounding tissues, which makes it less likely to roll during needle insertion. This vein is also less painful for patients when punctured due to its location and the type of surrounding tissue.

Choice B Reason:

The basilic vein is another option for venipuncture, but it is not typically the first choice. It is located on the medial aspect (inner side) of the arm and is more prone to rolling and injury because it is not as well anchored as the median cubital vein. Additionally, the basilic vein is located near nerves and arteries, which increases the risk of complications during venipuncture.

Choice C Reason:

The cephalic vein runs along the lateral aspect (outer side) of the arm and can be used for venipuncture. However, it is often more difficult to locate and has a tendency to roll, which can make venipuncture more challenging. It is usually considered after the median cubital vein.

Choice D Reason:

Veins on the underside of the wrist should generally be avoided for routine venipuncture because they are often smaller, can be more painful due to the proximity to nerves and tendons, and have a higher risk of complications. These veins are considered only when other sites are not available or are unsuitable for venipuncture.

Choice A Reason:

For blood donation, a 16- to 18-gauge needle is typically used because it is large enough to allow the rapid flow of blood without causing hemolysis (destruction of red blood cells). The larger gauge needle also helps in minimizing the time the donor has to spend during the donation process. Using a needle that is too small could slow down the blood flow and potentially damage the blood cells, which is not ideal for the recipient of the blood donation.

Choice B Reason:

A 19- to 21-gauge needle is commonly used for routine venipuncture but is not ideal for blood donation. These needles are smaller than the 16- to 18-gauge needles and would not facilitate the quick collection of the volume of blood typically required for a donation. They are more suitable for collecting blood samples for testing rather than for donation purposes.

Choice C Reason:

A 22- to 24-gauge needle is even smaller and is often used for patients with smaller veins, such as children or elderly patients. These needles would not be appropriate for blood donation as they could significantly slow the blood flow and increase the donation time, which could be uncomfortable for the donor.

Choice D Reason:

A 25- to 28-gauge needle is the smallest size commonly used in medical practice and is suitable for patients with extremely small or fragile veins. These needles would be impractical for blood donation due to their small size, which would not allow for the efficient flow of blood required for a donation.

Choice A Reason:

A multipart requisition involves multiple copies of a paper form, which can be prone to errors due to manual entry, misplacement, or illegible handwriting. While it provides physical copies for various departments, it is not the most accurate method compared to digital solutions.

Choice B Reason:

A manual requisition is similar to a multipart requisition but typically consists of a single form. It carries the same risks of human error and does not offer the benefits of automated tracking and data entry that come with electronic systems.

Choice C Reason:

An automated requisition is considered the most accurate method for receiving orders for specimen collection. It reduces the risk of human error associated with manual data entry and allows for better tracking and integration with laboratory information systems. Automated systems can also provide immediate feedback if there is an issue with the order, such as a missing patient identifier or a test code.

Choice D Reason:

A verbal requisition is the least reliable method as it depends on the memory and communication skills of the individuals involved. It lacks the documentation and verification steps present in written or automated methods, making it susceptible to misunderstandings and errors.

Choice A Reason:

CLIA, or the Clinical Laboratory Improvement Amendments, sets standards for all laboratory testing to ensure the accuracy, reliability, and timeliness of patient test results. While CLIA provides a framework for laboratory operation, it does not offer specific guidelines for chemical spill cleanup.

Choice B Reason:

OSHA, or the Occupational Safety and Health Administration, provides regulations to ensure worker safety, including protocols for handling hazardous materials. However, OSHA itself does not provide the specific cleanup procedures; instead, it requires workplaces to follow certain safety practices.

Choice C Reason:

SDS, or Safety Data Sheets, provide detailed information on chemicals, including their properties, health hazards, protective measures, and safety precautions, including spill response and cleanup procedures. In the event of a chemical spill, the SDS contains the most direct instructions for safe and effective cleanup, making it the primary reference for a phlebotomist in this situation.

Choice D Reason:

The CDC, or Centers for Disease Control and Prevention, focuses on public health and disease prevention. While the CDC provides guidelines for infection control and laboratory safety, it is not the primary resource for chemical spill cleanup procedures.

Choice A Reason:

A multipart requisition involves multiple copies of a paper form, which can be prone to errors due to manual entry, misplacement, or illegible handwriting. While it provides physical copies for various departments, it is not the most accurate method compared to digital solutions.

Choice B Reason:

A manual requisition is similar to a multipart requisition but typically consists of a single form. It carries the same risks of human error and does not offer the benefits of automated tracking and data entry that come with electronic systems.

Choice C Reason:

An automated requisition is considered the most accurate method for receiving orders for specimen collection. It reduces the risk of human error associated with manual data entry and allows for better tracking and integration with laboratory information systems. Automated systems can also provide immediate feedback if there is an issue with the order, such as a missing patient identifier or a test code.

Choice D Reason:

A verbal requisition is the least reliable method as it depends on the memory and communication skills of the individuals involved. It lacks the documentation and verification steps present in written or automated methods, making it susceptible to misunderstandings and errors.