|Year : 2022 | Volume
| Issue : 1 | Page : 71-76
COVID-19: Challenges and coping strategies in radiology departments in Nigeria
Olubukola A Omidiji1, Omolola Mojisola Atalabi2, Elizabeth A Idowu2, Aderemi Ishola3, Omodele A Olowoyeye1, Adeleye Dorcas Omisore4, KC Eze5, Muhammad S Ahmadu6, Ngozi R Dim7, Ismail Anas8, Adaobi C Ilo7, Sidikat A T. Ayodele9, Feyisayo Yvonne Daji10, Abdulsalam M Yidi10, Olubukola Khadija Ajiboye11, Kamaldeen O Jimoh10, Oluyemisi O Toyobo12, Ayesan M Onuwaje13, Nicholas Kayode Irurhe1, Adekunle O Adeyomoye1, Rachael A Akinola9, Rasheed Ajani Arogundade1
1 Department of Radiation Biology, Radiotherapy and Radiodiagnosis, College of Medicine, Lagos University Teaching Hospital, University of Lagos, Idi-Araba, Nigeria
2 Department of Radiology, University College Hospital, Ibadan, Oyo State, Nigeria
3 Department of Radiology, Federal Medical Centre, Asaba, Delta State, Nigeria
4 Department of Radiology, Faculty of Clinical Sciences, Obafemi Awolowo University Teaching Hospital, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
5 Department of Radiology, Faculty of Medicine, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra State, Nigeria
6 Department of Radiology, University of Maiduguri Teaching Hospital, Maiduguri, Borno State, Nigeria
7 Department of Radiation Medicine, Faculty of Medical Sciences, College of Medicine, University of Nigeria, Ituku Ozalla Campus, Enugu, Nigeria
8 Department of Radiology, Aminu Kano Teaching Hospital, Bayero University, Kano, Nigeria
9 Department of Radiology, Lagos State University College of Medicine, Lagos State University Teaching Hospital, Idi-Araba, Nigeria
10 Department of Radiology, National Hospital, Abuja, Nigeria
11 Department of Radiology, Cedarcrest Hospitals, Warri, Nigeria
12 Department of Radiology, Crestview Radiology, Lagos, Nigeria
13 Department of Radiology, Lily Hospitals, Warri, Nigeria
|Date of Submission||11-Apr-2021|
|Date of Acceptance||27-Sep-2021|
|Date of Web Publication||18-Mar-2022|
Omolola Mojisola Atalabi
Department of Radiology, University College Hospital, Ibadan, Oyo State
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Context: COVID-19 came suddenly, bringing to the fore the challenges inherent in the health system. In a developing country, such as Nigeria, which already had myriad problems with funds and equipment in the health sector. Aims: This study aims to examine the challenges encountered by the staff in Radiology facilities and how they combated the challenges. Settings and Design: A descriptive cross-sectional study of radiology facilities in Nigeria. Subjects and Methods: Radiologists from nine government and four private facilities who attended to COVID-19 patients were asked to fill questionnaires on challenges faced and their coping strategies. Responses were sent through E-mail. Statistical Analysis Used: Data from the responses were analyzed using Microsoft excel for Mac 2011 and presented as figures and tables. Results: Majority of the government 7 (77.8%) and private facilities 4 (100%) had no equipment dedicated only to COVID-19 patients. Seven (77.8%) government facilities complained of inadequate staff, poor availability of personal protective equipment (PPEs) 8 (88.9%), and lack of technology for remote viewing 7 (77.8%). Fear of cross-infection was a challenge in one of the facilities 1 (11.1%). Coping strategies adopted include ensuring less traffic in the department by discouraging walk-in patients and canceling non-emergent cases, booking suspected/confirmed cases for lighter times, using old film for face shields and cloth for facemasks, staff education on COVID-19 and preventive measures, and sending reports to physicians through E-mail. Conclusions: There were a lot of challenges during the COVID-19 crisis, with government hospitals experiencing more challenges than private facilities. The challenges included among others inadequate staff strength and lack of technology for remote viewing. Some were overcome using education and by production of facemasks/shields production using recycled materials.
| Abstract in French|| |
Le contexte: COVID-19 came suddenly, bringing to the fore the challenges inherent in the health system. Dans un pays en développement, comme Le Nigeria, qui avait déjà une myriade de problèmes de fonds et d'équipements dans le secteur de la santé. Objectifs : Cette étude vise à examiner les défis rencontrés par le personnel des établissements de radiologie et comment ils ont relevé les défis. Paramètres et conception: une section descriptive étude des installations de radiologie au Nigeria. Sujets et méthodes: Radiologues de neuf établissements publics et de quatre établissements privés qui ont participé aux patients COVID-19 ont été invités à remplir des questionnaires sur les défis rencontrés et leurs stratégies d'adaptation. Les réponses ont été envoyées par courrier électronique. Analyse statistique utilisée: Les données des réponses ont été analysées à l'aide de Microsoft Excel pour Mac 2011 et présentées sous forme de figures et de tableaux. Résultats: La majorité des établissements publics 7 (77,8 %) et privés 4 (100 %) ne disposaient d'aucun équipement dédié uniquement aux patients COVID-19. Sept (77,8 %) établissements publics se sont plaints d'un personnel inadéquat, d'une faible disponibilité des équipements de protection individuelle (EPI) 8 (88,9 %), et le manque de technologie pour la visualisation à distance 7 (77,8 %). La peur d'une infection croisée était un défi dans l'un des établissements 1 (11,1 %). Faire faceles stratégies adoptées comprennent la réduction de la circulation dans le service en décourageant les patients sans rendez-vous et en annulant les cas non urgents, en réservant les cas suspects/confirmés pour des périodes plus légères, en utilisant un vieux film pour les écrans faciaux et un tissu pour les masques faciaux, la formation du personnel sur COVID-19 et mesures préventives et l'envoi de rapports aux médecins par courrier électronique. Conclusions: Il y a eu beaucoup de défis pendant la COVID-19 crise, les hôpitaux publics étant confrontés à plus de défis que les établissements privés. Les défis comprenaient entre autres l'insuffisance la force du personnel et le manque de technologie pour la visualisation à distance. Certains ont été surmontés grâce à l'éducation et à la production de masques faciaux/boucliers utilisant des matériaux recyclés.
Mots-clés: défis, les stratégies d'adaptation, COVID-19, Nigeria
Keywords: Challenges, coping strategies, COVID-19, Nigeria, radiology facilities
|How to cite this article:|
Omidiji OA, Atalabi OM, Idowu EA, Ishola A, Olowoyeye OA, Omisore AD, Eze K C, Ahmadu MS, Dim NR, Anas I, Ilo AC, Ayodele SA, Daji FY, Yidi AM, Ajiboye OK, Jimoh KO, Toyobo OO, Onuwaje AM, Irurhe NK, Adeyomoye AO, Akinola RA, Arogundade RA. COVID-19: Challenges and coping strategies in radiology departments in Nigeria. Ann Afr Med 2022;21:71-6
|How to cite this URL:|
Omidiji OA, Atalabi OM, Idowu EA, Ishola A, Olowoyeye OA, Omisore AD, Eze K C, Ahmadu MS, Dim NR, Anas I, Ilo AC, Ayodele SA, Daji FY, Yidi AM, Ajiboye OK, Jimoh KO, Toyobo OO, Onuwaje AM, Irurhe NK, Adeyomoye AO, Akinola RA, Arogundade RA. COVID-19: Challenges and coping strategies in radiology departments in Nigeria. Ann Afr Med [serial online] 2022 [cited 2022 May 26];21:71-6. Available from: https://www.annalsafrmed.org/text.asp?2022/21/1/71/339935
| Introduction|| |
A lot has been written about the origin of COVID-19 and how it spread its tentacles from China to Europe and the United States until no country in the world was exempted. Within weeks the viral infection was worldwide, thus proving the claim that the world has become a global village. Scientists had predicted that morbidity and mortality rates would be catastrophic,, especially in developing countries, due to lack of facilities/equipment, overpopulation in cities, and generally poor healthcare., This created panic in many nations, and all hands were on deck to think outside the box on how to rise to the challenges.
In Nigeria, the anticipated high morbidity and mortality rates did not occur, in spite of the limitations, much to the amazement of scientists. The prevalence of COVID-19 cases in Nigeria as at June 2020 rose rapidly to 25,694, from a lone case in February 2020. Many reasons have been proffered– the age pyramid which showed Nigeria as a predominately youthful population with very few geriatric homes, increased immunity from past exposure to other coronaviruses, and an outdoor lifestyle.
The radiology department plays a pivotal role in the management of patients presenting with chest symptoms such as cough and breathlessness. More often than not, physicians send for Chest X-rays and Computed tomography for such patients, depending on the initial clinical diagnosis made and while awaiting the polymerase chain reaction (PCR) test.
In patients with moderate to severe lower respiratory tract infection symptoms, imaging is required to rule out or confirm COVID-19. It is also used to assess response to management in confirmed COVID-19 patients.,, Imaging modalities utilized include radiography, computed tomography, lung ultrasound, and magnetic resonance imaging for patients with neurologic symptoms. Those with COVID-19 and mild clinical features do not require imaging unless they are at risk of disease progression. There are also asymptomatic unconfirmed patients who are likely to present at the facility for other imaging requests unrelated to COVID-19 and therefore still have the ability to transmit the virus.
Many challenges in the radiology department have been described in literature,,,,,, such as poor infection control, paucity of personal protective equipment, lack of social distancing, inadequate staff, and dedicated imaging equipment. Some authors also describe what was done to combat these challenges.
This paper sets to determine the local challenges experienced in our environment as well as the coping strategies developed to combat the challenges.
| Subjects and Methods|| |
Nine randomly selected radiology departments in government-owned hospitals and four private facilities, with at least one from each of the six geopolitical zones of the country, certified by Nigeria Centre for Disease Control to attend to COVID patients were selected to participate in this study. They were asked to describe the challenges experienced in their departments during the COVID-19 crisis, as well as steps taken to mitigate the challenges between April and June 2020, using a structured questionnaire. E-mails were sent to radiologists at the hospitals, who also sent responses back through E-mail. Additional information was sought via phone calls to clarify responses, where necessary. All responses were collated and analyzed using Microsoft Excel for Mac 2011. They are presented as figures and tables.
Informed consent was obtained from the radiologists at the participating centers, and approval for the study was obtained from the LUTH Health Research Ethics Committee.
| Results|| |
A total of nine government facilities and four private facilities were included in the study. All the government facilities had challenges, while the private facilities had few challenges at the time of this report.
Majority of the government 7 (77.8%), and private facilities 4 (100%) had no equipment dedicated only to COVID-19 patients. All the 9 government facilities had CT scanners. Most 7 (77.8%), government facilities had only one computed tomography (CT) scanner, the others had 2 (22.2%) two functional CT scanners and could dedicate one to the COVID-19 patients. Three (42.8%) of the facilities with single CT scanners had dysfunctional ones. Three (75%) of the private facilities had single functional CT equipment.
Portable X-ray equipment was available in all the government facilities 9 (100%), seven (77.8%) had only one mobile X-ray machine, most 6 (66.7%) of which were nonfunctional at the time of the report. Two facilities had more than one functional portable X-ray equipment [Figure 1]. Three 3 (75%) of the private facilities had functional mobile X-ray equipment.
Personal protective equipment
The challenge common to most of the government facilities was the poor availability of personal protective equipment (PPEs) 8 (88.9%). Only one (27.3%) government facility had adequate PPEs provided by the hospital management [Figure 1].
Most of the facilities 7 (77.8%) noted that the number of staff available only allowed for limited rotation of staff to limit exposure to the virus-prone areas [Figure 1]. The private facilities had adequate staff.
Poor aeration of facilities was a challenge in 8 (88.8%) of the government facilities. Most also had inadequate waiting areas or holding areas for suspected patients 7 (77.8%). This was not a challenge for the private facilities.
Lack of Picture archiving and communication system (PACS) and electronic management system
Lack of picture archiving or electronic management systems or technology for remote viewing was also a challenge in most of the government facilities 7 (77.8%) [Figure 1]. No challenge was reported by the private facilities with regards to this.
Fear by radiologists and radiographers
Only 1 (11.9%) government facility reported fear of contracting the infection from patients and colleagues as a challenge, as the staff refused to attend to most patients without seeing a COVID-19 test result. Those with COVID-19 infection requiring CT or X-rays were turned back, with staff leaving their duty posts [Figure 1]. Fear was not a challenge at the private facilities.
Hand washing and sanitizers
None of the facilities had any challenge with the provision of handwashing and sanitizer equipment. All the facilities initially made use of modified Veronica buckets with taps, filled with water, and placed at the entrances of several offices, departments, and hospitals [Figure 2], later battery-operated taps were installed at the entrance of the private facilities. Hand sanitizers and soap were also provided.
Majority of the facilities described similar patterns of overcoming challenges experienced during the COVID period [Table 1].
Overcoming lack of adequate equipment
The seven facilities with functional mobile X-ray dedicated those to the holding areas to limit the spread of the infection. A facility described limiting investigation times of suspected and confirmed cases to periods where there was less traffic in the department and also planning the time such that the patient could be wheeled in, have investigations conducted, and was subsequently wheeled out immediately. The equipment room was thereafter closed down for disinfection with a downtime of up to 12 h. Non-COVID-related cases were attended to by 6 (66.7%) of the facilities before the confirmed cases.
Overcoming Poor availability of personal protective equipment
One of the government facilities described an ingenious way of recycling old X-ray films. Face shields were made using old films with the images removed with 1% chlorine bleach [Figure 3]. Another facility mentioned the recycling of N95 masks by wearing N95 masks with the normal facemasks over them so they could be recycled. Cloth masks were encouraged for non-medical staff, such as clerks with no direct contact with patients. All facilities appealed to the government and non-governmental organizations for help and funds, resulting in donations of face masks and shields.
Overcoming poor aeration of departments and lack of social distancing
All ((100%) had similar patterns of social distancing, Walk-in patients were discouraged, and the number of relatives escorting patients for investigations was also reduced to the barest minimum. All the government facilities stopped nonemergent investigations and intensified booking of patients for ultrasound, fluoroscopic, and breast imaging procedures. Standard operating protocols for the COVID period were drafted and approved by the administration/managements of the respective facilities. Rooms were decontaminated and equipment sterilized after each patient. Probes were cleaned with appropriate disinfectants. Seven centers 7 (77.8%) had markers on seats, which were enforced to ensure social distancing. Additional fans were procured, and air conditioning systems serviced to ensure adequate flow. Rooms were aerated after each The private facilities maintained their normal services; the sole private facility without mobile X-rays referred triaged patients to those with such facilities. All patients and relatives had to have face masks in at all times and were asked to wash hands or sanitize their hands with sanitizers at the entrance of the facilities.
Overcoming lack of dedicated areas
All the government 9 (100%) and private 4 (100%) facilities had personnel checking temperature at the entrance of the facility. Seven 7 (77.8%) with inadequate waiting areas had the patients with high recordings, or suspicious symptoms were sent to dedicated emergency locations for COVID screening. One (14.2%) facility described how reports of investigations were sent directly to the E-mails of the referring physicians. All the private facilities had reports sent to the patients' E-mails.
Overcoming lack of PACS and electronic management system
None of the seven government facilities affected were able to overcome this challenge; hence, there was delay in reporting the films with additional pressure on PPEs and increased risk of exposure to the virus since the radiologists had to physically go to the reporting room. Sanitizers were provided for use at the reporting rooms for decontamination.
Overcoming inadequate staff strength
Only patients that must come to the hospital were allowed to come as they were triaged over the phone while those needing follow-ups were attended to over the phone. This method allowed for rotation of staff in the hospital, while nonessential workers were to work from home or placed on call duty, thus allowing for maximization of the available staff and reducing work pressure. Staff who became symptomatic were tested and asked to quarantine for an average of 2 weeks and until symptoms abated. Vaccines were not available as at the time of the study.
The sole facility affected overcame this through continuing education of all members of staff on how to protect oneself from catching the virus and provision of personal protective equipment. Staff resumed attending to all patients, including those with COVID infections.
| Discussion|| |
The COVID era came unexpectedly and resulted in a lot of scrambling to appropriately address the challenges created by the situation. Personal protective equipment (facemasks, face shields, and gloves) became scarce and very expensive because these were no longer only needed by medical personnel but by the entire populace. There was also a lot of hoarding by merchants with the hope of making more profits from the sales of the equipment. People had to learn to manage and recycle used facemasks and shields and also make new ones from old material such as films and cloth, such as described in this study.
Politi and Balzarini in Italy described measures used to combat the crisis brought by COVID at their department, such as social distancing, special procedure rooms and wards for confirmed and suspected COVID patients, reduction in outpatient radiological examinations, provision of personal protective equipment (PPEs), provision/use of face masks for both patients and staff to combat the sanitary emergencies they faced. These measures are similar to those described in this study. They also mentioned another challenge not discussed in this study – economic downturn, with marked increase in expenditure and decrease in revenue, for which no solution was proffered. Economic challenge had not been analyzed at the time of the study.
In the early days, X-ray departments were purpose-built with radiation protection being uppermost in the minds of the contractors; hence, the rooms are leaded to reduce scatter with limited focus on aeration. The advice given for decontamination of equipment is to allow cross-ventilation, which unfortunately was not possible at most of the facilities. Newer departments and X-ray facilities have better aeration, which may account for the lack of complaints by the private facilities.
A major bane of low-medium income countries is lack of equipment, with one CT machine sometimes serving over 10 million people, as seen in this study. Most of the government facilities were tertiary ones, and yet most had only one CT and one mobile X-ray machine serving several patients and hospitals in the community, unlike similar radiological departments in developed countries, where equipment could be dedicated to imaging only COVID patients thus avoiding interaction with other patients.
Some recommendations for infection control have been made by several societies; these include disinfection of equipment using 2000 mg/L chlorine-containing disinfectant, wiping of the CT gantry with 75% ethanol, and closure of the CT room for about 1 h to allow ventilation and air circulation., This was a challenge in facilities in Nigeria as the sole equipment was unavailable during the period of aeration. Ultrasound equipment (keyboards, probes) and viewing stations should also be disinfected with alcohol-containing disinfectants or those recommended by equipment manufacturers. A number of the facilities had nonfunctioning equipment, which may be as a result of paucity of biomedical engineers who can maintain equipment or fix broken-down equipment.
Information systems and picture archiving systems are still very scarce in Nigeria with very few public facilities having the system in place as noted in this study. Part of the measures utilized to reduce foot traffic in the hospital in some studies,, included reorganization of the staff duty schedule to allow only a few people in the facility at a time. This would have been better achieved if there were facilities allowing remote viewing of images in place. Most of the facilities in this study complained of inadequate staff strength, so rotation of staff was not as effective, indirectly resulting in more staff being exposed than should be at a particular point in time. Redmond et al. also discussed the need to ensure judicious use of imaging as a major part of mitigating the risk of transmission to health care workers.
Fear of infection was described by one of the facilities as a major deterrent to patients obtaining adequate medical attention. The management of fear can be pharmaceutical or psychological, which includes cognitive therapy. Cognitive therapy was utilized in this case through adequate education and enlightenment of staff about the virus and protective measures. A similar experience was documented by Redmond et al.; they also noted that the fear was soon abolished through education.
Redmond et al. so mentioned rapid evolution of the disease as a challenge with an impact on radiologic findings. For radiologists, in particular, the need to keep abreast of the latest developments as relating to typical and atypical presentations (gastrointestinal, cardiac, neurologic) was emphasized so that such patients could immediately be isolated and tested. This should be done through research, regular training/retraining, and education. In this study, all the facilities had their staff educated. They took advantage of the numerous virtual meetings and presentations given by many international radiological societies for self-education and update.
Yu et al. also described challenges they attributed to the infection of five of their staff. These included loopholes in the patient triage (fever and history of exposure for isolation, whereas 1.2%–6% of asymptomatic patients could also infect others), failure to isolate suspected patients from ordinary patients, failure to follow standard procedures exiting contaminated and suspected contaminated areas, and discrepancy between imaging and nucleic acid detection. To overcome these challenges, they isolated those with positive nucleic acid detection regardless of CT chest findings. They introduced the paperless systems, enabled remote diagnosis by radiologists and portals for patients to check their results. Only one center in this study documented sending patients reports through E-mails. Remote diagnosis of cases was limited in our environment owing to most facilities lacking radiology information systems. Some of the patients are also not literate enough to manage digital communication. Many cannot afford android or iPhone.
A study in Barcelona also noted increased waiting times for procedures due to many cancellations. The workload increased, however in the chest radiology section due to increase in chest imaging requests. This is similar to what obtained in this study. Imaging was limited to emergencies. The Barcelona radiology department reduced their usual patient load of 350,000 annually by 70%–80% and cancelled all research. Work was limited to emergencies and oncology, as in this study. Other interventions they did include telephone consultations conducted pre- and post-interventional procedures, staff encouraged to work from home, and created a structured report template to guide reporting X-rays and CTs. Most facilities in this study also deferred non-emergent studies. Triaging was also conducted on the phone by some of the facilities.
According to Oleaga “Radiology departments must adapt to the new situation created by the pandemic, learn from it and reorganize working procedures to be prepared for new outbreak clusters in the future.”
| Conclusion|| |
The challenges encountered by staff in the Radiology departments brought to the fore issues that were inherent in the department before the advent of COVID-19 and included inadequate manpower, lack of equipment, PPEs and fear. The government hospitals had more challenges than the private establishments. These challenges were faced head-on with ingenious ways of overcoming them, with locally available /recyclable materials. Working procedures were re-organized to prevent undue staff exposure. All the facilities had adequate education on the virus and protective measures.
We are grateful to the management and staff of the various institutions in this study for their roles and contributions in the COVID-19 crisis.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Wang C, Horby PW, Hayden FG, Gao GF. A novel coronavirus outbreak of global health concern. Lancet 2020;395:470-3.
Ohia C, Bakarey AS, Ahmad T. COVID-19 and Nigeria: Putting the realities in context. Int J Infect Dis 2020;95:279-81.
Ghisolfi S, Almås I, Sandefur JC, von Carnap T, Heitner J, Bold T. Predicted COVID-19 fatality rates based on age, sex, comorbidities and health system capacity. BMJ Global Health 2020;5:e003094.
Amzat J, Aminu K, Kolo VI, Akinyele AA, Ogundairo JA, Danjibo MC. Coronavirus outbreak in Nigeria: Burden and socio-medical response during the first 100 days. Int J Infect Dis 2020;98:218-24.
Mossa-Basha M, Meltzer CC, Kim DC, Tuite MJ, Kolli KP, Tan BS. Radiology department preparedness for COVID19: Radiology scientific expert panel. Radiology 2020;296:E106-12.
Akl EA, Blažić I, Yaacoub S, Frija G, Chou R, Appiah JA, et al
. Use of chest imaging in the diagnosis and management of COVID-19: A WHO rapid advice guide. Radiology 2021;298:E63-9.
Redmond CE, Nicolaou S, Berger FH, Sheikh AM, Patlas MN. Emergency radiology during the covid-19 pandemic: The Canadian association of radiologists recommendations for practice. Can Assoc Radiol J 2020;71:425-30.
Cohen J, Rodgers YV. Contributing factors to personal protective equipment shortages during the COVID-19 pandemic. Prev Med 2020;141:106263.
Politi LS, Balzarini L. The radiology department during the COVID-19 pandemic: A challenging, radical change. Eur Radiol 2020;30:3600-2.
Santos RP, Pires ALA, Almeida RMVR, Pereira WCA. Computed Tomography Scanner Productivity and Entry-Level Models in the Global Market. Journal of Healthcare Engineering Volume 2017, Article ID 1304960, Pages 1-5. https://doi.org/10.1155/2017/1304960
Stogiannos N, Fotopoulos D, Woznitza N, Malamateniou C. COVID-19 in the radiology department: What radiographers need to know. Radiography (Lond) 2020;26:254-63.
Ekpo EU, Egbe NO, Azogor WE, Inyang SO, Upeh ER. Challenges of radiological equipment management policies in some northern Nigerian hospitals. S Afr Radiogr 2013;51:19-22.
Alhajeri M, Shah SG. Limitations in and solutions for improving the functionality of picture archiving and communication system: An exploratory study of PACS professionals' perspectives. J Digit Imaging 2019;32:54-67.
Yu J, Ding N, Chen H, Liu XJ, He WJ, Dai WC, et al
. Infection control against COVID-19 in departments of radiology. Acad Radiol 2020;27:614-7.
Oleaga L. How is the pandemic affecting radiology practice? Health Manag 2020;20:310-2.
[Figure 1], [Figure 2], [Figure 3]