E-ISSN:2456-3110

Research Article

Primary Dysmenorrhoea

Journal of Ayurveda and Integrated Medical Sciences

2023 Volume 8 Number 4 April
Publisherwww.maharshicharaka.in

A clinical study to evaluate the efficacy of Phala Taila Matra Basti in Kashtartava w.s.r. to Primary Dysmenorrhoea

Ashwini M.1*, Samuel S.2
DOI: http://dx.doi.org/10.21760/jaims.8.4.2

1* M Ashwini, Assistant Professor, Department of Prasuti Tantra & Stree Roga, ALN Rao Memorial Ayurvedic Medical college & Hospital, Koppa, Karnataka, India.

2 Sharon Samuel, Associate Professor, Department of Prasuti Tantra & Stree Roga, Sri Sri College of Ayurvedic Science and Research Hospital, Bengaluru, Karnataka, India.

Background: Female health is a primary factor to be considered for the wellbeing and productivity of both family and society. Her menstrual health has a great impact on her educational, social and economic progress. Although dysmenorrhea is not life threatening, it is found to have a profound impact on daily activities resulting in absenteeism.[1] Primary dysmenorrhea prevalence estimates range from 25% to 90% among women and adolescents Studies from India reported the prevalence range between 50% to 87.8% During menstruation, many women experience gastrointestinal upsets which are increased by analgesics and anti-inflammatory drugs, which also cause headache, dizziness, drowsiness and blurred vision. The drugs in this Taila are Vatakaphahara, Shoolahara, Udararogahara, Srotovishodana, Garbhashaya Shodana, Balya. Due to these properties, it helps in reducing symptom of Kashtartava. Basti (therapeutic enema) is the ideal treatment option for disorders of Vata. Phala Taila[2] is a preparation mentioned in Kashyapa Samhita for management of aggravated Vata in Prusta (back of the body), Uru (hip), and Janga Pradesha (calf muscle). Aim: To analyse the effect of Phala Taila Matra Basti in the management of Kashtartava w.s.r to Primary Dysmenorrhoea. Method: “A Randomized controlled clinical study to evaluate the efficacy of Phala Taila Matrabasti in Kashtartava w.s.r to Primary Dysmenorrhoea.” Result: Taking all subjective and objective parameter into consideration especially with effect size comparison clearly shows that Group B is much better with respect to most of the parameter in providing clinical relief. Conclusion: Dashamoola Ksheera Yoga Basti is more effective than Phala Taila Matra Basti in the management of Kashartava w.s.r. to Primary Dysmenorrhoea.

Keywords: Kashtartava, Primary Dysmenorrhoea, Matra Basti, Yoga Basti.

Corresponding Author How to Cite this Article To Browse
M Ashwini, Assistant Professor, Department of Prasuti Tantra & Stree Roga, ALN Rao Memorial Ayurvedic Medical college & Hospital, Koppa, Karnataka, India.
Email:
M Ashwini, Sharon Samuel, A clinical study to evaluate the efficacy of Phala Taila Matra Basti in Kashtartava w.s.r. to Primary Dysmenorrhoea. J Ayu Int Med Sci. 2023;8(4):9-16.
Available From
https://jaims.in/jaims/article/view/2399

Manuscript Received Review Round 1 Review Round 2 Review Round 3 Accepted
2023-02-25 2023-02-27 2023-03-06 2023-03-13 2023-03-19
Conflict of Interest Funding Ethical Approval Plagiarism X-checker Note
Nil Nil Yes 17%

© 2023by M Ashwini, Sharon Samueland Published by Maharshi Charaka Ayurveda Organization. This is an Open Access article licensed under a Creative Commons Attribution 4.0 International License https://creativecommons.org/licenses/by/4.0/ unported [CC BY 4.0].

Introduction

Primary Dysmenorrhoea is a condition characterized by severe lower abdominal pain during menstruation associated with other complaints like nausea, vomiting, diarrhea, headache, fatigue. Dysmenorrhoea affects 50% of menstruating women and is found to have a profound impact on the daily activities and may result in absenteeism from work or school. Thereby, it may accentuate the emotional distress brought on by pain. Prevalence of dysmenorrhoea in women of the reproductive age group is 70 - 91%, and severe pain contributes to 2 - 29%.[3] Systematic review of studies in developing countries performed by Harlow and Campbell (2002) has revealed that about 25-50% of adult women and about 75% of adolescents experience pain during menstruation, with 05-20% reporting severe dysmenorrhoea. The treatment of this disorder is still unsatisfactory in modern medicine as the usage of antispasmodic and analgesics drugs may cause many side effects like gastro intestinal upset, headache, dizziness, drowsiness and blurred vision. Kashtartava is expressed as “Kashtenmunchyatiti Kashtartavam”– Kashtartava is the condition where the Artava is discharged with great difficulty and pain. It has been compared to dysmenorrhoea based on the symptoms. Dosha -Vata Pradhana Tridosha; Dushya - Rasa, Rakta, Artava Sammurchana takes place in Garbhashaya and due to vitiation of Vyana and Apana Vayu the Aakunchana and Prasarana Kriya of Garbhashaya does not take place properly, this state resembles with the dysrhythmia of uterine muscles, which will hinder in proper flow of menstrual blood leading to Kashtartava. Basti is the ideal treatment option for disorders of Vata. It is the treatment modality indicated in all types of Yonivyapad. Phala Taila is a preparation mentioned in Kashyapa Samhita Khilasthana[2] in Bastiviseshenaniya Adhyaya for management of aggravated Vata in Prusta, Uru, Janga Pradesha (calf muscle), Gulma, Mutraghata (suppression of urine), Krimikoshta (abdominal parasites), and in Basti Vyapad. Most of the drug in this preparation contains Vatakaphahara, Shoolahara, Garbhashaya Shodana, Balya, Udararogahara properties. Due to these properties, it helps in reducing symptom of Kashtartava. Here in this study an attempt will be made to evaluate the efficacy of Phala Taila as Matra Basti in management of Kashtartava w.s.r to Primary Dysmenorrhoea.

Objectives

Primary: To evaluate the efficacy of Phala Taila Matra Basti in management of Kashtartava w.s.r. to Primary Dysmenorrhoea.

Secondary

1. To re-evaluate the efficacy of Dashamoola Ksheera Basti in management of Kashtartavas.r. to Primary Dysmenorrhoea.

2. To compare the efficacy of Phala Taila Matra Basti and Dashamoola Ksheera Yoga Basti in management of Kashtartavas.r. to Primary Dysmenorrhoea.

3. To understand Kashtartava in Ayurvedic classics w.s.r. to Primary Dysmenorrhoea.

Materials and Methods

Since the present study was a controlled study two drugs i.e., a standard and the test drug was selected, they are

1. Dashamoola Ksheera Yoga Basti

2. Phala Taila Matra Basti

Phala Taila Matra Basti[2]

Ingredients: Laghu Panchamoola, Madanaphala, Yava, Kola, Kulatta, Jala, Kushta, Satapushpa, Vacha, Yashtimadhu, Kutaja, Madana Beeja, Yavani, Pippali, Devadaru, Rasna, Devapushpa, Musta, Harenu, Bilwa, Priyangu , Ela, Tila Taila and Dadhi Mastu. Raw Drug were identified and approved by Dept. Dravya Guna. Phala Taila was prepared in pharmacy of Rasashastra and Bhaishjya Kalpana of Sri Sri College of Ayurvedic Science and Research Hospital, Bengaluru.

Control drug: Dashamoola Taila was procured from GMP certified pharmacy. Dashamoola Kwatha Choorna, honey was procured from SSCAS&RH, Bengaluru.

Sampling Method and Research Design

Source of data: A series of 30 subjects with were randomly selected, from the OPD and IPD of Sri Sri College of Ayurvedic Science and Research Hospital, Bengaluru. The selected 30 patients were divided into 2 equal groups of 15 patients. A detailed Proforma was prepared considering all points pertaining to the study


was prepared. The parameters considered for the study was scored on the basis of Standard methods and were analyzed statistically.

Research Design: It is an open labelled controlled clinical study with pre and post-test design, where 30 subjects with Kashtartava w.s.r. to Primary Dysmenorrhoea were selected for the study.

Diagnostic Criteria

1. Subjects with painful menstruation

2. Subjects with pain over lower abdomen, thigh or lower back during menstruation

3. Subjects with pain that subsides gradually after the onset of menstruation

Inclusion Criteria

1. Subject with age 18 - 30 years.

2. Subjects with regular menstrual cycle.

3. Subject suffering with Kashtartava for more than 2 consecutive cycles

4. Subjects with scanty or average bleeding during menstruation

5. Subject with history of analgesics during previous cycles

Exclusion criteria

1. Subject suffering from Secondary dysmenorrhoea.

2. Subjects with irregular cycles

3. Subjects with abnormal uterine bleeding

4. Subject using IUCD.

5. Subjects who have undergone major abdominal or pelvic surgery

6. Subjects with HIV, HbSAg or VDRL positive

7. Subjects suffering from systemic diseases, thyroid dysfunction

8. Basti Ayoga

Lab investigations

  • USG
  • Hb%
  • ESR
  • RBS
  • Urine R&M

Table 1: Showing intervention of the study

  Group A Group B
Medicine Phala Taila Dashamoola Ksheera
Mode of administration Matrabasti Yogabasti
Dose 1½ Pala (72ml)[4] Dashamoola Ksheera Niruha - 500ml Dashamoola Taila Anuvasana - 60ml
Duration of treatment 8 days 8 days
Duration of study 2 Months 2 Months
Follow up 1 assessment – after 1st cycle 2nd assessment – after 2nd cycle 1 assessment – after 1st cycle 2nd assessment – after 2nd cycle

Assessment Criteria

Subjective Criteria

Table 2: Showing Pain Intensity[5]

Grade  Pain Intensity
0 Absent
1 Mild (pain does not interfere with daily activity
2 Moderate (daily activity hampers, relieves with analgesic)
3 Severe (does not get relieved with analgesics)

Nature of pain site of pain

Table 3: Showing nature of Pain

Grade Nature of Pain
0 Absent
1 Occasionally (mild)
2 Dull (continuous)
3 Spasmodic (cramp like)

Table 4: Showing site of Pain

Grade Site of Pain (Abdomen, Lowback, Thigh)
0 No pain
1 One site
2 Two site
3 Three site

Duration of Pain

Table 5: Showing duration of Pain

 Grade  Duration
 0 No Pain in menstruation
 1 Pain continue for 12 hours
 2 Pain continue for 12-24 hours
 3 Pain continue more than 24 hours

Objective Criteria

  • VAS Scale[6]
  • Multi- Dimentional Scoring System[7]

  • WaLIDD (Working ability, Location, Intensity, Days of pain)[8]
  • Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q-SF)

Observation

The present study revealed the presence of Kashtartava Age - 56.67% belonged to the age group of 22-25. the incidence rate of Primary dysmenorrhoea is predominantly confined to adolescent girls. Marital Status - subject 86.6% were Un married Primary dysmenorrhea is more common in un married girls.[9] Marriage may cure by removing the tension of a long engagement and by providing happiness and security, on the other hand if it proves disharmonious, it can cause dysmenorrhoea. Education and occupation - 53% were graduation Students are more prone to Primary dysmenorrhoea due to educational stress, strain, and anxiety over examinations, just before and during menstruation most of the women are efficient physically and more unstable emotionally these factor alone lower the pain threshold. Family history - 70% had positive Family history. Thus, this suggests that genetic factor is involved in the pathogenesis. Socio economic status - Upper middle class (57%). As Textual reference Dysmenorrhoea common in affluent society study population is not sufficient more study is required.

Subjective Parameter: Non-parametric values like Nature of pain, Intensity of pain, and Site of pain, Duration of pain and Associated symptoms were analyzed using:

  • Friedman’s test within the groups
  • Mann Whitney U test between the groups

Objective Parameter: Parametric values like VAS Scale, Multi-dimensional Scoring, WaLIDD, Q-LES-Q-SF were analyzed using:

  • Unpaired T Test Between the Groups
  • Repeated Period ANOVA Within the Groups

Effect Size Determination

Table 6: Showing effect size determination nature of pain

Assessment of nature of pain
  AT (After 1st cycle) FU (After 2nd cycle)
Group A 1.33 ± 0.61 1.66 ±0.97
Group B 0.8 ± 0.56 1.06 ± 0.73
  MD – 0.53 SD pool- 2.26 MD – 0.59 SD pool- 3.32
ESD 0.11 (S) 0.13 (S)

Table 7: Showing effect size

The effect size after treatment observed for Group A in comparison to Group B is 0.11 and for follow up period 0.13 - both these values fall under small effect size difference hence with respect to this parameter the clinical effect observed for Group B is only marginally better in comparison to Group A.

Table 8: Showing determination pain intensity

Assessment of pain intensity
  AT (After 1st cycle) FU (After 2nd cycle)
Group A 1.53 ± 0.91 1.8± 1.73
Group B 0.8 ± 0.56  1.06± 0.7
  MD – 0.74 SD pool- 5.11 MD – 00.73 SD pool- 5.110
ESD 0.92 (L) 0.125 (S)

Effect size after treatment for Group A in comparison to Group B is 0.92 which falls under higher end of large effect size different; for follow up score the effect size difference was -0.125 which falls under small effect size. Based on this it can be inferred that pain intensity reduction in Group B after treatment is much higher in comparison to the Group A. However, this difference is small with respect to follow up score.

Table 9: Showing Effect Size Determination Site of Pain

Assessment of Site of Pain
  AT (After 1st cycle) FU (After 2nd cycle)
Group A 1.66± 0.89  1.73± 0.96
Group B  0.8± 0.56 1.13 ± 0.74
  MD – 0.85 SD pool- 2.87 MD – 0.600 SD pool- 3.319
ESD 0.23 (S) 0.123(S)

The effect size difference for Group A in comparison to Group B is 0.23 and for follow up score-0.123-both these values fall under small size band hence the efficacy for this parameter is marginally better in Group B.

Table 10: Showing Effect Size Determination Duration of Pain

Assessment of Duration of Pain
  AT (After 1st cycle) FU (After 2nd cycle)
Group A 1.06 ± 0.45 1.33 ± 0.61
Group B 0.86 ± 0.51 0.8 ± 0.56
  MD – 0.20 SD pool- 1.86 MD – 0.53 SD pool- 2.26
ESD  0.12(S) 0.112(S)

The effect size difference for group A in comparison to Group B is 0.12 and for follow up score 0.112- both these values fall under the small size band hence the difference in clinical efficacy is small.


Comparison between the group for clinical efficacy based on statistical analysis showed that there is no significant difference between the two groups with respect to the effect observed on Arthava Pramana, Praseka, Swedadhikyata, Chardi, Vankshanashoola, Kati Shoola, Janu Shoola and Shirasoola. Further the apparent difference between the groups for effect size was also not remarkable hence it was not calculated. Hence no clinical effect size was calculated.

Objective Parameter

Table 11: Showing Effect Size Determination VAS Scale

Assessment of VAS Scale
  AT (After 1st cycle) FU (After 2nd cycle)
Group A 5.33 ± 1.07 5.73 ± 1.28
Group B 4.83 ± 1.06 1.28± 1.33
  MD – 0.5 SD pool- 4.12 MD – 0 SD pool- 5.50
ESD  0.12(T) 0 (T)

The effect size value for VAS scale on AT is 0.12 for FU day – 0, both fall under Trivial band. This indicates that in this Group B has clinically marginally effective in comparison to Group A.

Table 12: Showing Effect Size Determination Multi Dimensional Scoring System

Assessment of Multi Dimensional Scoring System
  AT (After 1st cycle) FU (After 2nd cycle)
Group A 4.67 ± 1.29 5.27 ± 0.96
Group B 3.47 ± 1.76 4.33 ± 1.83
  MD – 1.19 SD pool- 5.97 MD – 0.93 SD pool- 5.65
ESD  0.20(S) 0.166 (S)

The effect size value scoring multi-dimensional scoring system on AT is 0.20 for FU day – 0.166, both fall under small band. This indicates that in this Group B has clinically effective in comparison to Group A.

Table 13: Showing Effect Size Determination WaLIDD

Assessment of WaLIDD
  AT (After 1st cycle) FU (After 2nd cycle)
Group A 1.2 ± 0.41 1.6± 0.63
Group B 0.8 ± 0.41 1.0± 0.53
  MD – 0.399 SD pool- 1.58 MD – 0.60 SD pool- 2.25
ESD  0.25 (S) 0.266 (S)

The effect size value WaLIDD scoring scale on AT is 0.25 for FU day – 0.266, both fall under small band. This indicates that in this Group B has clinically effective in comparison to Group.

Table 14: Showing Effect Size Determination Q-LES-Q-SF

Assessment of Q-LES-Q-SF
  AT (After 1st cycle) FU (After 2nd cycle)
Group A 69.4 ± 10.22 61.47 ± 10.49
Group B 73.6 ± 9.17 70.6± 16.18
  MD – 4.199 SD pool- 37.60 MD – 9.12 SD pool- 52.80
ESD  0.11(S) 0.17(S)

Discussion

Discussion on Drug Review

Phala Taila is a preparation mentioned in Kashyapa Samhita Khila Sthana in Bastiviseshenaniya Adhyaya for management of aggravated Vata in Prusta, Uru, Janga Pradesha, Gulma, Mutraghata, Krimikoshta, and in Basti Vyapad. It contents 26 drugs, most of the drug in this preparation acts as Vatakaphahara, Vedanastapana (anodynes), Garbhashaya Shodana, Balya (strength promoters), Udararogahara, Kashtartava (Rajorodha), Kashtartava - Kulattha, Kushta, Kantakarai, Yavani, Madanaphala; Shiroshoola (headache), Deepana (appetizer), Pachana (digestives), Vatanulomana. Among 28 drugs in Phala Taila; Rasa - Madura - 13; Katu - 13; Tikta - 14; Kashaya - 9; Veerya - Ushna - 15; Sheeta - 11; Vipaka - Katu -16; Amla - 1; Madura - 9; Dosha - Vatakaphahara - 16; Tridoshashamaka - 3; Vatapitta Shamaka - 2; Vatahara - 1; Pittakaphashamaka - 4.

Discussion on drug probable mode of action of Phala Taila

Based on Rasa

  • Tikta Rasa is having property of Kaphaghna, Lekhana, Shodana.
  • Katu Rasa is having properties like Kapha Shamaka acts Agni Deepana, Srotovivarana property acts as vasodilation which in turn reduces the pain.
  • Madhura Rasa: Vata-Pitta Samaka. Acts as Dhatu Vardhana, Balya, Jeevaniya, Ayusha, Sandhanadara, Kantya, Murchaprashamana, Indriya Prasadana all this properties help in reducing associated symptoms like Srama, Aruchi, Tamodarshana, etc.

Based on Gunas

  • Laghu Guna possess Pachana, Lekhana properties

  • Tikshna Guna acts Kapha Vatahara, which will expel the Dosha
  • Snigdha and Guru Guna possess

Based on Virya: Ushna Virya possess Vatahara & Kaphahara properties acts Deepana, Pachana Karma.

Based on Karma: All dugs of Phala Taila have the actions like Vatakaphahara, Vedanastapana, Garbhashaya Shodana, Balya, Udararogahara, Kashtartava (Rajorodha), Shiroshoola, Deepana, Pachana, Vatanulomana. The properties of Phala Taila such as Snigdha, Guru, Ushna are opposite to the properties of Vata. Thus, these properties of Phala Taila acts against Vata and help in subsiding the Shoola.

By Kaphavataharatva, Ushnatva & Katutva removes Sanga of Artavavaha Srothas, thereby it avoids Sanga and Vimarga of Artavavaha Srothas, By Vataghnata and Shulaghnata effect it directly acts on pain. Margavarodha and Dhatukshaya are Nidana of Vataprakopa. In this disease of Kashartava Margavarodha can be taken as obstruction in normal pathway of menstruation. The property of Vatanulomana corrects the path of Apana Vata and help in Artava Niskramana Kriya without causing pain.

Mode of action of Basti: Acharya Vagabhata says the Virya of Basti is conveyed to Apana and then to Samana Vata, which may regulate the function of Agni. It then goes to Udana, Vyana, and Prana, thus providing its efficacy all over the body. Basti therapy is considered as prime among all the therapeutic measures, especially for management of Vatavyadi, and some physicians accept it as a complete therapeutic measure. Basti Dravyas can act as Vatahara, Shulahara, Shothahara, Srotoshodhaka, Yogavahi, Agnideepaka, and Rasayana. Our Acharyas have considered the rectum (Guda) as the root of the body (Mula of Sharira). At the same time Basti by pacifying Vata, restores the disturbed Kapha and Pitta at their original seats and thus helps in breaking the pathogenesis. Thus, according to Ayurveda, the Veerya (active principle) of the ingredients used in the Basti gets absorbed and then, through the general circulation, reaches at the site of the lesion and relieves the disease.

Modern pharmacokinetic studies have also proved that drug administration via the rectum can achieve higher blood levels of the drug than administration

through the oral route due to partial avoidance of hepatic first-pass metabolism. The rectum has a rich blood and lymph supply and drugs can cross the rectal mucosa as they can other lipid membranes. Thus, un-ionized and lipid-soluble substances are readily absorbed from the rectum. The portion absorbed from the upper rectal mucosa is carried by the superior hemorrhoidal vein into the portal circulation, whereas that absorbed from the lower rectum enters directly into the systemic circulation via the middle and inferior hemorrhoidal veins. Thus, administration of drugs in the Basti form has faster absorption and provides quicker results.

Overall Assessment

Table 14: Showing Overall Assessment

Parameter Group A Group B Clinical Effect size
Duration of pain 33% 48% B>A
Site of Pain 38% 72% B>A
Working ability 27% 51% B>A
Q-LES-Q-SF 22% 32% B>A
 Total 35% 67.66%  

Conclusion

The present study was done to evaluate the efficacy of Phala Taila Matra Basti (Study group) and Dashamoola Ksheera Yoga Basti (Control group) in Kashartava w.s.r. to Primary Dysmenorrhoea. Objectives were statistically analyzed using repeated measure Anova and Paired t test. Each medicine was found to be effective within the group with a highly significant p value <0. 001 and mean difference. But percentage of improvement were high in Group B. Taking all subjective and objective parameter into consideration especially with effect size comparison clearly shows that Group B is much better with respect to most of the parameter in providing clinical relief. Thus, Alternate hypothesis (H2) is accepted. Dashamoola Ksheera Yoga Basti is more effective than Phala Taila Matra Basti in the management of Kashartava w.s.r. to Primary Dysmenorrhoea.

Reference

1. Shabnam Omidvar, Fatemen Bakouel, Fatemeh Nasiri Amiri & Khyrunnisa Begum. Primary Dysmenorrhoea and Menstrual Symptoms in Indian Female Student: Prevalance, Impact and management. Global journal of health science. 2016


Aug;8(8):135-144 published online 2015 Dec 17 Doi 10.5539/gjhs. v8n8

2. Vriddha Jeevakiya, Kasyapa Samhitha, vidyotini hindi commentary and translation by Sri Satyapala Bhisahagacharya; khila sthana Ch.8, ver89-96, Reprinted edition 2002, Varanasi: Chaukambha Santhan; 2002, p.43

3. Dutta. D.C, Textbook of Gynecology. 8th edition. New Delhi:Jaypee Brothers Medical Publishers;2020. p.147-150

4. KavithaP, Neelambikai N: Prevalence of dysmenorrhoea among women in the reproductive age group in Peelamedu area in Coimbatore. National journal of Physiology [internet] 2016; p 1-13.

5. Upasana Sharma, Sushila Sharma. A clinical study on effect of Vijayadi vati on Kashtartava w.s.r to Primary Dysmenorrhoea. IAMJ [internet].2019august; vol 7(8): page 1220-26. Available- http://www.iamj.in/posts/images/upload/1219 1226pdt

6. Faezeh Ghaderi, Shahin Banakar, Shima Rostami. Effect of pre- cooling injection site of pain perception in pediatrics dentistry: A Randomized clinical trial. DSJ. Nov 2013/vol10/issue 6: page 79094. Available –source of support –nil, conflict of interest: none declared.

7. Nebahat Ozendogan, Deniz Sayiner, Unal Ayranci, Alaettin, Sevgi Giray. Prevalence and predictor of Dysmenorrhoea among student at a university in Turkey. International journal of Gynecology and Obstetrics [internet].2009; 39-43 Available – www.Elsevier.com/locate/ijgo

8. Anibal A Teheran Luis Gabrial Pineros. WaLIDD score, a new tool to diagnosis of dysmenorrhoea and predict medical leave in university students.International journal of women’s health[internet]. 2018:10 p 35-45 Available –https;www.dovepress.com by 186.147.155.44

9. Malhotra Narendra, Jeffcoate’s Principles of Gynaecology. 9th edi. New Delhi: Jaypee Brothers Medical Publishers; 2019 p.725