A Survey of Therapeutic Drug Monitoring Status in China : Therapeutic Drug Monitoring

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Review Article

A Survey of Therapeutic Drug Monitoring Status in China

Yin, Tao.; Liang, Hongyan; Huang, Qi; Zhou, Boting; Tang, Mimi; Lou, Jiang; Xiang, Dong

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Therapeutic Drug Monitoring 45(2):p 151-158, April 2023. | DOI: 10.1097/FTD.0000000000001060



Therapeutic drug monitoring (TDM) is an important combination of pharmaceutical and clinical work. In general, it refers to a pharmaceutical clinical discipline that explores and establishes the mechanism, technology, method, and clinical standard for personalized drug therapy, and further uses the research outcomes in clinical treatment, to maximize the rational use of the drugs. In particular, the drug exposure, pharmacological markers, or pharmacodynamic indicators are measured for the patients, and a quantitative pharmacology model is adopted to develop a personalized drug delivery plan, which is suitable for the patients based on the drug treatment window.1,2

During the 1950s and early 1960s, TDM started gaining momentum, and gas–liquid chromatography, nitrogen and phosphorus detector, radiation immune detection technology, and homogeneous enzyme‐linked immunoassay technology were initially used for the assessment. In addition, awareness regarding the relationship between drug concentration in the body and treatment effect was also used. In the 1970s, the emergence of high-performance liquid chromatography further promoted the development of TDM. Importantly, China started performing TDM‐based clinical pharmaceutical research in 1979, which developed rapidly in the 1980s.3 Pharmacy, clinical laboratory cross participation, and multidisciplinary integration constituted an important medical and technical force, especially for organ transplantation, epilepsy, asthma, cardiovascular diseases, and other drugs, to provide a scientific means for personalized treatment. At present, TDM is routinely practiced in China for anti‐epileptic drugs, immunosuppressants, anti‐arrhythmic drugs, antipsychotic drugs, antibiotics, and chemotherapeutics, similar to other nations. Interestingly, TDM is also performed for toxic pesticides, such as paraquat, which are useful for defining prognosis.

By the end of 2018, China included a total of 12,032 public hospitals. Among these, 1442 were top tertiary hospitals, which performed a major proportion of diagnosis and treatment for out‐patients, in‐patients, and serious diseases. Surveillance of therapeutic drugs in China mainly relies on the distribution of public hospitals. Nationwide surveys for the assessment of TDM service have been previously performed in Malaysia.4 However, none of these surveys included a comprehensive and in‐depth TDM questionnaire, with survey subjects and contents from all across the nation. Thus, the present study aimed to conduct a survey to analyze the current status of TDM in China, and thus compare the status quo of top-grade tertiary hospitals (3A hospitals) with non–top tertiary hospitals (other than 3A hospitals). This nationwide questionnaire survey was developed based on previous studies.5–7 Importantly, questionnaires were issued to clinicians, pharmacists, and laboratory physicians in the present study, unlike the surveys conducted before.


A cross-sectional survey of 156 questions was conducted, which included single choices, multiple choices, and open-ended questions (see Table 1, Supplemental Digital Content, https://links.lww.com/TDM/A634). The survey questions were related to hospital location, grade, and the type of all respondents (Table 1). Different designs were made for clinicians, pharmacists, and laboratory physicians. For clinicians, we inquired about which specific drugs they want to assess for TDM, and their opinions and suggestions on TDM work. For TDM pharmacists and laboratory physicians, we investigated the number and type of TDM facilities of their hospitals, the number of routine examination items and annual sample size, and specific monitored drugs, and their methods, as well as their comments and suggestions toward promoting and improving the TDM work.

TABLE 1. - Areas Covered and Item Distribution of the Questionnaire Used for the Survey of TDM in China
Item Number Aspects Items of Question
1–4 Basic information The hospital location, grade, type, and occupation of the respondents.
5–24 For clinicians items Hope to develop the kinds of TDM drugs and biological sample species, clinical requirements, opinions, and understanding on existing problems of TDM.
25–155 For TDM pharmacist and clinical laboratory physicians items Monitoring facilities, detection annual sample size, detection methods, and interpretation of detection reports; suggestions for improving TDM work. Test methods, concentration range and charge of the specific projects.
156 Information of the respondents Name and contact.

In particular, mobile‐based WeChat software was used to develop the questionnaire method “Questionnaire Star” (https://www.wjx.cn) and distributed among pharmacists, clinicians, and clinical laboratory physicians nationwide, through the way of WeChat diffusion on August 20, 2019. The questionnaires were collected at the data terminal of the “Questionnaire Star” on August 30, 2019. Data were analyzed using the Statistical Package for Social Sciences (SPSS) program (Ver. 26.0). Descriptive statistics with frequencies and percentages were used, as per the requirement. For the collected data, percentages were calculated based on the number of respondents who answered each particular question. To evaluate the differences in the availability of TDM service based on hospital characteristics, Mann–Whitney test was used for skewed data. P <  0.05 was considered to be statistically significant.


Distribution of Respondents Participating in the Questionnaire

In the present study, a total of 475 questionnaires were collected from 25 provinces and municipalities in China. In particular, 364 questionnaires were collected from general hospitals and 111 from specialized hospitals (see Figure 1, Supplemental Digital Content, https://links.lww.com/TDM/A634). Importantly, 383 questionnaires were obtained from top tertiary hospitals, whereas 92 were collected from non–top tertiary hospitals. The study involved data received from 95 clinicians, 139 TDM pharmacists, and 6 clinical laboratory physicians. The remaining 235 questionnaires were received from dispensing pharmacists, scientific researchers, postgraduate students, and others. The effective rate of this survey was reported to be 50.5%, wherein a total of 240 responses were considered to be valid (clinicians, TDM pharmacists, and laboratory physicians) (Figure 1). This was comparable to the response rate reported in previous studies.4,5,8,9

The occupational distribution of participants effective rate (50.5%) refers to the ratio of total number of clinicians. TDM pharmacists and clinical laboratory physicians to the total number of respondents.

Testing Equipment and the Specific Workload of TDM

The responses received from TDM pharmacists and clinical laboratory physicians showed that the number of TDM detection instruments used for the assessment was mostly ≤2. The number of instruments used in top tertiary hospitals was recorded to be ≤2 (89, 73.6%), 3–5 (27, 22.5%), and ≥6 (5, 4.2%). In comparison to this, the number of instruments used in non–top tertiary hospitals was ≤2 (23, 95.8%) and 3–5 (2, 4.2%). Thus, the number of instruments used in top tertiary hospitals was more than non–top tertiary hospitals, and the difference was found to be statistically significant (Mann–Whitney test, P = 0.017). The number of drug species monitored in the top and non–top tertiary hospitals was recorded to be 6–15 (56, 46.6%) and ≤5 (16, 66.7%), respectively. Thus, the number of drugs assessed in top tertiary hospitals was more compared with non–top tertiary hospitals, and the difference was statistically significant (Mann–Whitney test, P = 0.015). Most participants reported that the annual sample size was 100–1000 (35.5% from top tertiary hospitals and 54.2% from non–top tertiary hospitals respondents). However, the overall annual sample size was reported to be higher in top tertiary hospitals than non–top tertiary hospitals (P = 0.008) (Table 2).

Importantly, 160 of 203 (78.8%) respondents from top tertiary hospitals and 22 of 37 respondents (59.5%) from non–top tertiary hospitals stated that they received or provided a TDM test report (Mann–Whitney test, P = 0.012). As expected, pharmacists in top tertiary hospitals provided a more complete interpretation of the TDM report. Interestingly, most respondents, from both types of hospitals, did not care regarding which department should perform TDM (Mann–Whitney test, P = 0.838) (Table 2).

The Current Situation of TDM for the Investigation of Drugs

The results obtained from clinicians showed that clinicians in top tertiary hospitals were more interested in developing programs for β‐lactamase inhibitor (64, 78.0%), olanzapine (62, 75.6%), alprazolam (59, 72.0%), carbamazepine (56, 68.3%), valproic acid (55, 67.1%), and glucocorticoids (51, 62.2%). In case of non–top tertiary hospitals, clinicians were more inclined toward TDM programs for β‐lactamase inhibitor (12, 92.3%), glucocorticoids (11, 84.6%), olanzapine (9, 69.2%), carbamazepine (9, 69.2%), fentanyl (8, 61.5%), and morphine (8, 61.5%) (Figure 2).

The drug types and specific drugs clinician hopes to develop for TDM.

The study also investigated the number of hospitals, testing methods used for monitoring concentration, and fees charged for some of the projects that were routinely included in TDM. The results showed that Vancomycin was the most developed project, in top tertiary hospitals (92, 76.0%) and non–top tertiary hospitals (20, 83.3%). Importantly, the top tertiary hospitals performed more projects for valproic acid (84, 69.4%), methotrexate (71, 58.7%), carbamazepine (68, 56.2%), phenytoin sodium (63, 52.1%), and cyclosporine (56, 46.3%). In case of non–top tertiary hospitals, more projects were performed for cyclosporine (56, 46.3%), voriconazole (46, 38.0%), tacrolimus (45, 37.2%), methotrexate (71, 58.7%), valproic acid (84, 69.4%), and carbamazepine (68, 56.2%). These projects showed high consistency in the top and non–top tertiary hospitals. The most commonly used detection method included high-performance liquid chromatography, immunization, 2D-LC, or LC-MS, depending on the nature of the specific drug to be assayed. The results for monitoring the concentration showed that only phenytoin sodium (10–20 mcg/mL) exhibited a consistent concentration range during monitoring., whereas most others showed varying monitoring concentration ranges such as voriconazole, cyclosporine, olanzapine, clozapine, carbamazepine, theophylline, digoxin, and others (Table 3). Importantly, most of the hospitals charged no more than ¥200 for TDM, depending on the drug tested and methods used for assessment.

TABLE 2. - Progress of TDM Work in Top Tertiary Hospitals and Non–Top Tertiary Hospitals
Hospital Characteristics Top Tertiary Hospitals Non–Top Tertiary Hospitals P (0.05)
Quantity of facilities for TDM N = 121(%) N = 24(%) 0.017*
 ≤2 89 (71.3%) 23 (95.8%)
 3–5 27 (22.5%) 1 (4.2%)
 ≥6 5 (4.2%) 0 (0%)
Number of monitored species N = 121 N = 24 0.015*
 ≤5 48 (40.0%) 16 (66.7%)
 6–15 56 (46.6%) 7 (29.2%)
 16–25 16 (13.3%) 0
 >25 1 (0.1%) 1 (5.1%)
Annual sample size (cases per yr) N = 121 N = 24 0.008*
 <100 30 (24.8%) 9 (37.5%)
 100–1000 43 (35.5%) 13 (54.2%)
 1000–3000 23 (19.0%) 2 (8.3%)
 >3000 25 (20.7%) 0 (0%)
Conduct TDM testing department N = 203 N = 37 0.838
 Pharmacy department 86 (42.4%) 14 (37.8%)
 Clinical laboratory 22 (10.8%) 6 (16.2%)
 Unsure 95 (46.8%) 17 (46.0%)
Whether to provide test report N = 203 N = 37 0.012*
 Yes 160 (78.8%) 22 (59.5%)
 No 43 (21.2%) 15 (40.5%)
*P < 0.05, statistically significant.

Comments and Suggestions on TDM Work

As per the clinicians, the main causes and proportion for the inconsistency in the results between TDM and clinical assessment were improper sample transportation and storage (68, 71.6%), inaccurate nurse sampling time (56, 58.9%), inaccurate medication timing (55, 57.9%), and inaccurate laboratory measurements (49, 51.6%). In the role that clinical pharmacists are expected to play in participating in TDM, the collected responses showed that 47 (49.5%) respondents wished clinical pharmacists to provide actionable clinical regimen adjustment suggestions, 44 (46.3%) expected pharmacists to help doctors in making/designing follow‐up monitoring plans, 42 (44.2%) wished that pharmacists should use the professional knowledge of pharmacy to interpret the results reasonably, 35 (36.8%) expected pharmacists to design monitoring plans in advance, and 33 (34.7%) expected pharmacists to assist in observing patients' adjusted clinical responses.

According to TDM pharmacists and clinical laboratory physicians, the accuracy of test results could be improved by the strengthening of quality control (144, 99.3%), regular calibration of instruments (132, 91.0%), timely measurement of samples (124, 85.5%), and fine-tuning of relevant technical guidelines (122, 83.6%). Concerning the strategies that can be used to improve clinicians' recognition of TDM work, 133 (91.7%) respondents believed that the level of clinical intervention should be improved, 116 (80.0%) suggested that propaganda should be strengthened, and 111 (76.6%) considered that interpretation of TDM results should be provided (Table 4).

TABLE 3. - Results for Monitoring the Concentration
Projects Top Tertiary, N = 121 (%) Non–top Tertiary, N = 24 (%) Detection Methods (Multiple choice) (n, %) Monitoring of Concentration (n, %) Charge (n,%)
Vancomycin 92 (76.0) 20 (83.3) HPLC (56, 50.0)
Immunization (44, 39.3)
2D-LC (14, 12.5)
LC-MS (18, 16.1)
10–20 mg/L (107, 95.5)
Others (5, 4.5)
<¥100 (50, 44.6)
¥100–200 (61, 54.5)
>¥200 (1, 0.9)
Voriconazole 46 (38.0) 5 (20.8) HPLC (27, 52.9)
Immunization (3, 5.9)
2D-LC (14, 27.5)
LC-MS (15, 29.4)
1–5 mg/L (41, 80.4)
1–5.5 mg/L (5, 9.8)
0.5–5mg/L (3, 5.9)
Others (2, 3.9)
<¥100 (18, 35.3)
¥100–200 (28, 54.9)
>¥200 (1, 2.0)
Tacrolimus 45 (37.2) 5 (20.8) Immunization (44, 88)
LC-MS (3, 6.0)
GC-MS (2, 4.0)
2D-LC (1, 2.0)
5–15 ng/mL (42, 84.0)
>6 ng/mL (1, 2.0)
Other (7, 14.0)
<¥100 (2, 4.0)
¥100–200 (16, 32.0)
>¥200 (32, 64.0)
Ciclosporin 56 (46.3) 7 (29.2) HPLC (9, 14.3)
Immunization (50, 79.4)
2D-LC (2, 3.2)
LC-MS (3)
100–450 μg/L (53, 84.1)
Other (10, 15.9)
<¥100 (3, 4.8)
¥100–200 (21, 33.3)
>¥200 (39, 61.9)
Olanzapine 16 (13.2) 1 (4.2) HPLC (7, 41.2)
2D-LC (9, 52.9)
LC-MS (4, 23.5)
10-20 ug/L (13, 76.5)
Other (4, 23.5)
<¥100 (6, 35.3)
¥100–200 (11, 64.7)
Clozapine 17 (14.0) 1 (4.2) HPLC (11, 61.1)
2D-LC (4, 22.2)
LC-MS (5, 27.8)
GC (3, 16.7)
10-20ug/L (13, 72.2)
Others (5, 27.8)
<¥100 (6, 33.3)
¥100–200 (12, 66.7)
Valproic acid 84 (69.4) 15 (62.5) HPLC (37, 37.4)
2D-LC (12, 12.1)
LC-MS (9, 90.9)
GC (7, 70.1)
Immunization (43, 43.4)
50–100 mg/L (96, 97.0)
Others (3, 3.0)
<¥100 (41, 41.4)
¥100–200 (57, 57.6)
>¥200 (1, 1.0)
Carbamazepine 68 (56.2) 13 (54.2) HPLC (43, 53.1)
2D-LC (11, 13.6)
LC-MS (9, 11.1)
Immunization (25, 30.9)
4–12 mg/L (79, 97.5)
Others (2, 2.5)
<¥100 (33, 40.7)
¥100–200 (46, 57.8)
>¥200 (2, 2.5)
Phenytoin sodium 63 (52.1) 10 (41.7) HPLC (41, 56.2)
2D-LC (8, 11.0)
LC-MS (8, 11.0)
Immunization (18, 65.8)
10–20 µg/mL (73, 100) <¥100 (28, 38.4)
¥100–200 (43, 58.9)
>¥200 (2, 2.7)
Theophylline 39 (32.2) 12 (50.0) HPLC (31, 60.8)
2D-LC (4, 7.8)
LC-MS (4, 7.8)
Immunization (16, 31.4)
5–20 mg/L (47, 92.2)
Others (4, 7.8)
<¥100 (20, 39.2)
¥100–200 (29, 56.9)
>¥200 (2, 3.9)
Digoxin 42 (34.7) 11 (45.8) HPLC (14, 26.4)
LC-MS (9, 17.0)
Immunization (31, 58.5)
0.8–2.0 μg/L (48, 90.6)
Others (5, 9.4)
<¥100 (25, 47.2)
¥100–200 (25, 47.2)
>¥200 (3, 5.6)
Methotrexate 71 (58.7) 3 (12.5) HPLC (37, 50.0)
2D-LC (12, 16.2)
TLC (3, 4.1)
LC-MS (8, 10.8)
Immunization (24, 32.4)
Multiple choice
24h:5–10 μmol/L (60, 81.1)
48h:0.5–1 μmol/L (55, 74.3)
72h:<0.2 μmol/L (55, 74.3)
72h:<0.1 μmol/L (6, 8.1)
Others (2, 2.7)
<¥100 (23, 31.1)
¥100–200 (46, 62.2)
>¥200 (5, 6.7)

TABLE 4. - The Comments and Suggestions From Respondents
Questions of the Survey N Proportion (%)
Clinicians considered the main reasons for the inconformity of TDM results with clinical practice (N = 95)
 Improper storage and transportation of specimens 24 68 71.6%
 Inaccurate nurse sampling time 56 58.9%
 Inaccurate medication time 55 57.9%
 Inaccurate laboratory measurement 49 51.6%
Clinicians considered the value of pharmacists in clinical practice (N = 95)
 Provide information on efficacy, safety, and interactions of drugs 83 87.4%
 Pharmacists participate in clinical rounds and case discussions 66 69.5%
 Provides interpretation of TDM results 57 60.0%
 Timely supply of newly marketed drugs 46 48.4%
 The role which clinicians wish pharmacists play in TDM (N = 95)
 Provide suggestions on adjustment of medication regimen 47 49.5%
 Interpretation test results 42 44.2%
 Assist doctors to develop follow-up monitoring plans 44 46.3%
 Design monitoring plans in advance 35 36.8%
 Assist to observe the patient's adjusted clinical response 33 34.7%
How to improve the reliability of TDM detection results (N = 145)
 Strengthen quality control 144 99.3%
 Equipment calibration 132 91.0%
 Timely sample determination 124 85.5%
 Develop technical guidelines 122 83.6%
How to improve clinicians' recognition of TDM (N = 145)
 To improve the clinical outcome of TDM intervention 133 91.7%
 Strengthen communication with clinicians 116 80.0%
 Provide interpretation of TDM reports to enhance the recognition of clinicians 111 76.6%


Current Situation of TDM Between the Top and Non–top Tertiary Hospitals

The present study compared the differences in TDM work for top tertiary hospitals and non–top tertiary hospitals. As expected, the facilities and workload of top tertiary hospitals resulted in more advantages. In China, the “3 Grades and 10 levels” hospital system exists, wherein the top tertiary hospitals (3A hospitals) are the highest‐ranking medical institutions with the best medical resources.10 These hospitals handle a major proportion of outpatients, inpatients, and major disease diagnoses and treatment. In TDM, top tertiary hospitals are characterized by better equipment, technology, and abundant sources of samples. Such an unequal distribution of medical resources is also common in other countries.11 A study conducted in Malaysia reported that hospitals with more beds offered better TDM services.4

In drug varieties that clinicians wanted to assess, top tertiary hospitals and non–top tertiary hospitals were found to be consistent. β‐lactamase inhibitor, olanzapine, carbamazepine, and glucocorticoids were reported to be the main projects that clinicians were interested in (Figure 2). β-Lactam antibiotics are widely used in clinical anti-infection treatment, which have a wide antibacterial spectrum and low toxicity, although because of the complexity of pathophysiologic state, they lead to pharmacokinetics and pharmacodynamics change, and there are often insufficient dosage or cumulative poisoning.12,13 It has become a trend to optimize the administration scheme based on pharmacokinetics/pharmacodynamics parameters through TDM. However, there is no consistent guidance on the interpretation of TDM results and dosing adjustment that limits the implementation of TDM for these drugs.14 Adverse reactions and individual differences of some drugs affect the treatment, such as olanzapine and carbamazepine. TDM is an important method for ensuring drug efficacy and controlling side effects in clinical practice.15

In drug varieties that have already been performed, vancomycin, valproic acid, methotrexate, carbamazepine, cyclosporine, and voriconazole were the most common projects for which TDM had been performed (Table 3). Most importantly, this suggested similarity in clinical work in different levels of hospitals. The Outline of the Plan for the National Medical and health service system (2015–2020), examined and approved by The State Council of China, calls for “minor diseases at the grassroots level, serious diseases in the hospital, and rehabilitation at the community-based hospitals.”16,17 Patients may be gradually extended to basic hospitals in the future, with the advancement of graded diagnosis and treatment. Accordingly, the clinical demand for TDM in non–top tertiary hospitals may also increase.

Which Department Should Undertake TDM Work?

The results of the survey showed that most of the participants did not care regarding which department should undertake TDM. The setting of the TDM laboratory varies between different countries.4,18 The pharmacy department and biochemistry department are the main departments that usually perform TDM. Previous reports from South Africa, India, and Turkey showed that the TDM laboratory was part of the pharmacology department.19 A part of Australian institutions performed simple tests in a clinical laboratory, whereas relatively complex therapeutic drugs were professionally tested by the clinical pharmacology departments.20 Similarly, there is no clear regulation on which department should perform TDM in China as well. The biochemistry department tends to use immunoassay for monitoring therapeutic drugs. In comparison to the laboratory, the pharmacy department is characterized by a profound pharmaceutical background, and more professional instruments, such as chromatographic and mass spectrometry devices, are used for analysis. The detection cost is usually high, whereas the results are relatively more accurate. More importantly, pharmacists can provide interpretation for test reports and medication guidance.

Inconsistent Monitoring Concentration Range

The results of the study showed that the monitored concentration ranges were mostly in conformity. The monitored concentration ranges for some of the drugs, such as voriconazole, olanzapine, clozapine, cyclosporine, and others, may vary depending on the medical institution or the type of testing method used. For example, 3 concentration ranges were recorded during monitoring of voriconazole, 1–5 mg/L, 1–5.5 mg/L, and 0.5–5 mg/L. Individualized medication guidelines for voriconazole recommend that the target steady‐state concentration range for the Chinese population is 0.5–5 mg/L (strong recommendation, medium-quality evidence). It has been previously specified that 0.5 mg/L and 1 mg/L are the lower limits for ideal voriconazole target valley concentration, but differences have been reported in the quality of evidence, wherein 1 mg/L was associated with low-quality evidence.21 Some studies have previously shown that the use of voriconazole to maintain the serum concentration between 1.0 and 6.0 mg/L during treatment may help to optimize the clinical success rate and minimize toxicity.22 Voriconazole is susceptible to organ function and individual-specific differences. Most of the patients with a fungal infection that are treated using voriconazole usually display a relatively critical condition, and the combination of drugs used for the treatment is quite complex.21 These differences may lead to differences in monitoring concentration ranges. Population pharmacokinetic studies may assist in providing stronger evidence for agreeing to the standardized monitoring concentration range.

According to the present investigation, the application of TDM for general projects costs no more than ¥200. However, immunosuppressants, such as cyclosporine and tacrolimus, involve slightly higher charges. This is mainly attributed to the use of immunoassay tests, which are provided by commercial companies using costly immunokits, resulting in higher charges. Attempts are being made to gradually bring testing kits into the coverage of medical insurance in China. In addition, strategies, such as the centralized purchase of drugs and the adoption of centralized procurement, may play an important role in controlling testing costs and stabilizing testing fees.

How to Improve the Clinicians' Recognition and Service Level of TDM

As per the survey results, the annual sample size was mainly concentrated in a small area, whether in top or non–top tertiary hospitals. Here, 2 sets of data are available showing that in 2018, the number of outpatient visits in hospital A was 3.53 million, with 17,820 cases for TDM, whereas in hospital B, outpatient visits were 3.5 million, with 6916 cases for TDM. The low clinical submission rate is an important reason for the small sample size for TDM. Thus, it is important to identify the causes for this low submission rate.

Some previous studies have shown that in the absence of group consultation, the requirements of clinicians cannot be identified, and the monitoring results cannot be explained well and applied, resulting in a low submission rate.9,23 No matter which department implements TDM, the clinical pharmacist should ideally make scientific interpretations for the test data to provide reasonable drug treatment recommendations.24 However, the results of the present survey showed that the interpretation of TDM results was not standardized and unified. In fact, some of the institutions did not make/provide necessary interpretations reports. Division of TDM, Chinese Pharmacological Society published expert consensus on “The Interpretation of Therapeutic Drug Monitoring Results.”25 The report emphasized the importance of the explanation of results by pharmacists. In particular, the purpose and process of interpretation of results were clarified, and the professional qualifications of the participants involved in the interpretation of results were emphasized.

Various factors that contribute to low inspection rates include long waiting times to receive results from the monitoring department and the absence of unified quality standards.9 The results of this questionnaire suggest that strengthening quality control, equipment calibration, timely sample determination, and developing technical guidelines are important means to ensure the quality of testing. In the clinical laboratory quality management system, the test quality requirements are ensured by implementing internal quality control and external quality assessment (EQA). Internal quality control regulates the operations and activities conducted outside the laboratory, whereas EQA, also known as proficiency testing, involves monitoring the accuracy of results among laboratories; Continuously and objectively evaluate test results in laboratories, finding systematic errors and making correction, and ensuring results comparability among laboratories.26 However, the limited proficiency testing programs currently available do not cover most and new tests. National Center for Clinical Laboratories is responsible for the quality management and control of clinical laboratories in China,27 which launched the national “EQA Investigation Plan for antibiotic drugs, antifungal drugs, antitumor drugs, psychotropic drugs and antidepressants”28 covering 33 drugs, which represents a positive effort to expand the EQA program toward meeting the clinical needs. In addition, we believe that the perfect TDM laboratory standards and certification work can serve as an important guarantee for laboratory testing ability.

In addition, the involvement of pharmaceutical technicians with a certain level of knowledge and proper training for standardized professional technical operation and regular operation is necessary.29,30

New monitoring methods, such as dried blood spot, molecular testing, and biomarkers assessment, have become popular in the past few years. Dried blood spot is a simple and fast method used to extract samples. Importantly, dry samples do not require refrigeration and provide the advantage of long‐term storage time. Molecular testing and biomarkers assessment could be used to obtain appropriate drug treatment schemes in advance, to prevent the generation of drug resistance.30 The application of these new technologies could further aid in the improvement of the level of TDM.


This survey was a large-scale survey involving pharmacists, clinicians, and laboratory physicians from medical institutions in China. The results of this survey objectively reflect the current situation of TDM work in Chinese hospitals. Pharmacokinetic studies based on a larger population can provide a basis for a unified monitoring concentration range. A complete clinical laboratory quality management system can be achieved to ensure the test quality and improve the interpretation rate of test reports by strengthening cooperation with clinical departments and introducing new technologies that may provide new ideas for improving the TDM service level. Cumulatively, this survey provides an objective, scientific, and valuable reference basis for the formulation of improvement strategies and the effective implementation of TDM work.


The survey did not cover the whole country, and the distribution of participants was biased. In areas close to our institutions, peers showed greater enthusiasm for this survey. This may be because of some limitations in the way of questionnaire promotion.


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therapeutic drug monitoring; nation-wide survey; China; hospital grade

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