• Users Online: 917
  • Print this page
  • Email this page


 
 
Table of Contents
ORIGINAL ARTICLE
Year : 2022  |  Volume : 27  |  Issue : 4  |  Page : 362-370

Immediate anxiety and depression disorders during the initial stage of the 2019 coronavirus disease (Covid-19) epidemic among the general population in Nigeria


1 Department of Community Medicine, Osun State University, Osogbo, Nigeria
2 United Nations Office on Drugs and Crime, Abuja, Nigeria
3 Department of Community Medicine, LAUTECH Teaching Hospital, Ogbomoso, Nigeria
4 Department of Mental Health, State Specialist Hospital, Osogbo, Nigeria

Date of Submission21-Feb-2022
Date of Decision15-May-2022
Date of Acceptance17-Jun-2022
Date of Web Publication22-Sep-2022

Correspondence Address:
Sunday O Olarewaju
Department of Community Medicine, Osun State University, Osogbo
Nigeria
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijmh.ijmh_18_22

Rights and Permissions
  Abstract 

Background: During the initial stage of Covid-19 outbreak in Nigeria, the government took drastic steps in controlling it; this included a total lockdown which left many with fears and worries about their health and household economy. The mental health of people in the society was becoming an issue that cannot be ignored. There was a dearth of information on the impact of Covid-19 on the mental health of the general population. Objectives: This study was therefore conducted to explore the prevalence of immediate anxiety and depression disorders and to identify associated factors during the initial stage of Covid-19 outbreak in Nigeria. Materials and Methods: The study was conducted in 2020 and was cross-sectional analytical in design. The study population included Nigerians above the age of 18 years. A total of 305 people participated in the study. Data were collected using a structured electronic questionnaire and analyzed using IBM SPSS version 25. Based on the Hospital Anxiety and Depression Scale (HADS), respondents were categorized into normal, having borderline, or having psychological disorders (anxiety or depression). Results: The median age of respondents was 30 years (interquartile range 23, 41.5). Three hundred and four respondents were aware of Covid-19. One hundred and twenty-five (41.0%) were assessed to be normal during the initial stage of Covid-19 in Nigeria, 44 (14.4%) had borderline psychological disorder, and 136 (44.6%) had either anxiety or depression. Respondents with occupation classified as others were found to be 52.1% times less likely to have anxiety or depression disorders when compared with civil servants (P = 0.045; 95% confidence interval = 0.23 - 0.99). Conclusion: Our study shows that anxiety and depression were widespread during the initial stage of Covid-19 outbreak. Mental health services would be essential in taking care of the psychological needs of Nigerians, especially those who have experienced and survived the scourge of the pandemic.

Keywords: Anxiety and depression, Covid-19, Nigeria


How to cite this article:
Olarewaju SO, Jegede OS, Ijitade G, Akande AM. Immediate anxiety and depression disorders during the initial stage of the 2019 coronavirus disease (Covid-19) epidemic among the general population in Nigeria. Int J Med Health Dev 2022;27:362-70

How to cite this URL:
Olarewaju SO, Jegede OS, Ijitade G, Akande AM. Immediate anxiety and depression disorders during the initial stage of the 2019 coronavirus disease (Covid-19) epidemic among the general population in Nigeria. Int J Med Health Dev [serial online] 2022 [cited 2022 Oct 7];27:362-70. Available from: https://www.ijmhdev.com/text.asp?2022/27/4/362/356622




  Introduction Top


The Covid-19 pandemic created a major public health concern around the world, with governments stepping up their efforts to halt the spread of the virus. The emergence of Covid-19 prompted a global response from all countries, including Nigeria, in order to combat the common threat.[1] Since the first confirmed cases were discovered in Wuhan, China, Covid-19 has caused unprecedented levels of mortality and morbidity, culminating in massive global public health crises.[2] The disease is caused by a novel coronavirus, having structural similarities to the gene that causes severe acute respiratory syndrome (SARS). As on March 14, 2022, the Nigeria Centre for Disease Control (NCDC) had reported 254,945 confirmed cases across the country, since the first reported case of the disease in Nigeria.[3]

Covid-19, like SARS, is a beta-coronavirus that can be transmitted to humans through intermediate hosts,[4] but the precise mechanism of transmission is unknown. Virus-laden respiratory droplets have been detected in a growing number of patients,[5] indicating that human-to-human transmission is possible. It has the potential to spread asymptomatically and has a typical incubation period of 5.2 days with significant variation between patients.[6] Symptoms of infection include fever, chills, cough, coryza, sore throat, difficulty breathing, myalgia, nausea, vomiting, and diarrhea.[7] Infected older males with medical problems are more likely to become infected and have worse outcomes.[7] Severe cases may result in cardiac injury, respiratory failure, acute respiratory distress syndrome, and death.[7]

As a result of the lockdown and travel restrictions, businesses were compelled to close, leading to increased unemployment and low pay.[8] Because of the uncertainty surrounding this negative economic effect, several members of the household have experienced psychological problems.[9] Maintaining social distance through fewer social activities has had a negative influence on social interactions, resulting in anxiety, concern, grief, bad sleep, despair, and suicidal ideation.[8] The symptoms of mass quarantine or self-quarantine include anxiety, distress, frustration, melancholy, loneliness, denial, insomnia, despair, self-harm, and suicide ideation.[10] The loss of liberty, separation from family, uncertainty about disease progression, a lack of basic necessities, and disruption of everyday life are all elements that contribute to these issues.[11] Individuals experienced extreme distress following the quarantine period as a result of financial loss, prejudice, societal rejection, and discrimination, according to records.[12] According to Dubey et al.,[12] having a Covid-19-infected acquaintance or relative generates stress and anxiety. Covid-19 survivors and contacts caring for very ill patients, as well as those who were widowed, in China experienced symptoms of anxiety, despair, and post-traumatic stress disorder.[13]

Previous research in epidemic-affected areas has discovered that imposed restrictions negatively affect people’s emotions.[14] Many studies have looked into people’s immediate psychological reactions during the Covid-19. For instance, a study assessed the psychological impact of the Covid-19 pandemic on a community during the outbreak and discovered the emergence of previously undiagnosed disorders and mental illnesses.[15] Isolation during a pandemic weakens basic stress-relieving techniques such as physical activity and spiritual coping, leading to heightened mental and physical stress.[13] Despite the previous and ongoing researches on this topic, only a few studies have attempted to assess Nigerians’ psychological reactions to the Covid-19 pandemic in the short term.

This study was therefore conducted to determine the psychological disorders experienced by Nigerians during the Covid-19 pandemic. The knowledge of study participants on Covid-19 was also investigated.


  Materials and Methods Top


Study design

This study was cross-sectional analytical in design.

Study setting

This study was carried out in Nigeria. An online survey was conducted using a structured questionnaire adapted from previous studies and the Hospital Anxiety and Depression Scale (HADS). The questionnaire assessed the knowledge of respondents on Covid-19 and the immediate anxiety and depression disorders during the initial stages of Covid-19 outbreak in Nigeria.

Study population

The study population was the general populace in Nigeria.

Inclusion criteria

The inclusion criteria include Nigerians above the age of 18 years who have access to internet services or a device that can be used to complete electronic forms.

Exclusion criteria

Exclusion criteria include individuals who, despite having access to the internet and devices that can be used to complete Google Forms, do not have the technical knowledge of how to complete electronic Google Forms.

Sampling technique

A simple random sampling technique was used to select respondents for the study. The sampling frame includes all members in a chosen WhatsApp group.

Sample size determination

The minimum sample size was determined using Leslie Fisher’s formula for calculating the sample size for prevalence studies:



where:

n = sample size,

z = normal deviate at 95% confidence interval =1.96,

p = prevalence of psychological disorders in the general population,

q (complementary probability) =1−p,

d = level of precision was set at 0.05.

The assumed prevalence of psychological disorder (anxiety) was 78.6% from a previous study.[16]

Using P = 0.786 and the level of precision set at 0.05

then



To compensate for non-responses, misplaced, or improperly completed questionnaires, the calculated sample size was increased by 10% (0.10).



This gave a minimum total sample size of 287 people.

Instrument for data collection

A structured questionnaire (with a mix of close-ended questions and Likert scale), which was designed by the research team after an extensive review of literature, was used for data collection. The questionnaire was completed by the respondents online (using Google Forms). In order to control access to the survey and ensure one response per person, respondents were asked to sign into their Google account before they could access the questionnaires. The questionnaire had four sections:

Section A: sociodemographic data on the age, gender, tribe, religion, designation, marital status, and highest educational level;

Section B: knowledge of respondents on Covid-19;

Section C: assessment of symptoms of depression and anxiety among respondents;

Section D: brief COPE on immediate psychological disorders using the HADS.

Instrument validation and pre-testing

Face and content validity were determined by the research team, by encouraging all the researchers to review the questionnaire items and provide comments and inputs. Each section of the questionnaire was matched with the predetermined objectives, and the validity of the instrument was determined in terms of its relevance, layout, and format. A pre-test was then conducted among 30 people (about 10% of the study population) on three different WhatsApp groups (10 per WhatsApp group). Revisions were made based on observations and feedbacks from study participants.

Methods of data collection

Due to the feasibility of carrying out a community-based face-to-face survey during this period of lockdown, data collection was conducted online. A one-page recruitment poster was designed and posted on various WhatsApp groups across the country. This poster contains brief information about the study title, aim, procedures, declarations of confidentiality of responses, and the link to the online questionnaire. Invitation for participation in the study was sent via WhatsApp to as many groups as possible, and participants were asked to post the information above and survey link on other WhatsApp groups they belong to. The online questionnaire provided better chances of preventing contamination of information that may arise if respondents were to complete the questionnaire in the presence of other respondents. The study was conducted in April 2020 over a period of 4 weeks.

Method of data analysis

The data were downloaded from Google drive, coded, compiled, and saved on a password-protected Excel spreadsheet, made only accessible to the research team. Data were then analyzed using IBM SPSS version 25. Descriptive and inferential statistical analyses were used.

Median and interquartile range (IQR) were used to describe respondents’ age, whereas frequency and percentages were used to describe categorical data. Regarding knowledge of Covid-19, correct responses to questions were given a score of 1 each, whereas 0 was given for incorrect responses. The scores were computed, and a mean score was obtained for all the respondents. The highest score possible was 25 and the mean score was 20. Respondents with scores equal to or more than the mean score, i.e., 20, were regarded as having good knowledge, whereas those with scores lower than the mean score, i.e., 20, were regarded as having poor knowledge.

Anxiety and Depression disorder scoring was done using the HADS, and the highest score possible was 21. Those with score ranging from 0 to 7 were categorized as normal, 8 to 10 as borderline abnormal, and 11 to 21 as abnormal case. The borderline abnormal and the abnormal cases were then merged as one category and referred to as psychological problem, whereas normal remained as the other category.

Bivariate and multivariate analyses were done using logistic regression to check for statistical association among sociodemographic status, knowledge, and immediate psychological disorders. The statistical significance level of less than 0.05 was assigned for all statistical analyses.


  Results Top


A total of 305 questionnaires were analyzed. The sociodemographic characteristics of participants are displayed in [Table 1]. The median age of respondents was 30 years (IQR 23, 41.5), and 93 (30.5%) were less than 24 years old, followed by 85 (27.9%) people within the age of 25–34 years. One hundred and seventy-nine respondents (58.7%) were females, and 152 (49.8%) were single. In terms of educational status, 300 (98.4%) had tertiary level of education. As regards occupation, 93 (30.5%) were students, 88 (28.9%) were civil servants, and 42 (13.8%) were public servants. In terms of religion, 254 (83.3%) were students.
Table 1: Sociodemographic characteristics of study participants

Click here to view


[Table 2] displays the level of awareness of respondents. Three hundred and four respondents were aware of Covid-19. Displayed on [Table 3] is the knowledge of participants about the symptoms of Covid-19, its mode of spread, complications, treatment, and mode of prevention. Two hundred and ninety-nine correctly stated that the virus can spread during coughing or sneezing. Two hundred and ninety-two (95.7%) respondents knew fever as a symptom of Covid-19, 125 (41.0%) and 222 (72.8%) correctly identified muscle pain and fatigue as symptoms of Covid-19, and 302 (98.7%) knew that cough is a symptom of Covid-19. In terms of Covid-19 complications, 282 (92.5%) knew that not all cases of the disease will develop severe symptoms and 222 (72.8) dispelled the statement that most people infected with the disease will die. Two hundred and ninety-four (96.4%) knew that there was no effective treatment for Covid-19. In terms of the measures of preventing the virus, 301 (98.7) correctly identified facemasks, 302 (99.0) correctly mentioned regular washing of hands with soap and water, and 299 (98.0) opined to isolation and treatment of people infected with the virus.
Table 2: Awareness about Covid-19

Click here to view
Table 3: Knowledge of Covid-19 among study participants

Click here to view


Based on computed mean knowledge score, 204 (66.9%) respondents had good knowledge of Covid-19, whereas 101 (33.1%) had poor knowledge of Covid-19 [Figure 1].
Figure 1: Overall knowledge of Covid-19 among respondents

Click here to view


Based on the HADS, respondents were categorized into normal, having borderline, or having psychological disorders (anxiety or depression). One hundred and twenty-five remained normal during the initial stage (first wave) of Covid-19 in Nigeria, 44 (14.4%) had borderline psychological disorder, and 136 (44.6%) had either anxiety or depression [Table 4].
Table 4: Category of psychological disorders among respondents

Click here to view


[Table 5] shows, on a Likert scale, the symptoms of depression and anxiety experienced by respondents. A lot of times, 53 (17.4%) people turned to work or other activities to take their minds off things, 61 (20.0%) had taken actions to try to make the situation better, 66 (21.5%) accepted the reality of the fact that it has happened, and 61 (20.0%) tried to find comfort in religion or spiritual beliefs. Other results are as presented in [Table 5].
Table 5: Assessment of symptoms of depression and anxiety among respondents

Click here to view


[Table 6] shows the association among sociodemographic status, knowledge, and immediate psychological disorders. Three variables (age, marital status, and occupation) were found to be associated with psychological disorders during the bivariate analysis. In the multivariable analysis, done to assess the individual effects of the variables by controlling confounders, only occupation was found to be significantly associated with psychological disorders. It was found that respondents with occupation classified as others were 52.1% times less likely to have psychological disorders when compared with civil servants at a P-value of 0.045 and confidence interval of 0.233, 0.985.
Table 6: Association among sociodemographic status, knowledge, and immediate psychological disorders

Click here to view



  Discussion Top


A large proportion of our respondents were between the age of 25 and 54 which is similar to what was reported by Kang et al.[15] This underscores the fact that the study used an online data collection approach, and the young and the middle age are more likely to use the internet than the children and elderly.

There were nearly equal numbers of males and females, providing a template for a possible gender comparison. There was no substantial link between gender and psychological disorders in this study. This finding was similar to that of a previous study conducted in Nigeria[16] but differs from the findings from other studies, where females were found to have a higher frequency of anxiety disorders than males.[13],[15],[17],[18] Married people were found to be less likely to have psychological problems. This could be linked to the fact that following the emergence of Covid-19, married persons might have received some forms of assistance from their partner, which helped them feel less depressed and anxious.

In terms of the general public’s initial psychological reaction to the Covid-19 epidemic in Nigeria, the proportion of participants who had borderline or severe psychological problems in this study was very good compared with the findings from studies conducted in Spain and India where a large proportion of participants had severe depression.[13],[15],[17],[18] The reason for this difference in findings could be that many infected individuals in those countries had poor clinical outcomes (including high case fatality rates) compared with Nigeria. Furthermore, a high level of discrimination against infected people, as well as the stigma connected with the diagnosis of new cases, may have contributed to high levels of depression in those countries.

The significantly lower likelihood of having psychological disorders among individuals whose jobs were unclassified could be because being financially secured can act as a defense mechanism against psychological disorder. Many small- and medium-scale businesses were forced to close because of the lockdown imposed, and many people lost their jobs as a result, leaving them with little or no savings to survive. The type of occupation one does before the initial stage (first wave) of Covid-19 might have determined how financially capable and psychologically stable an individual appears to be.

The proportion of respondents who were aware of symptoms of Covid-19 in this study was very good; majority of the participants knew fever, fatigue, cough as a symptom of Covid-19, and about half of them correctly identified muscle pain as symptoms of Covid-19. Our findings are consistent with the findings of other researchers’ studies conducted in Saudi Arabia, in which a large proportion of respondents (95%) were aware of Covid-19. This suggests that the general public accessed sufficient amount of information about the disease from government and health authorities during the outbreak. Higher levels of satisfaction with the health information obtained may assist to mitigate the psychological response of the outbreak and to reduce pain, anxiety, and depression.[19] Our findings revealed that up to date and accurate health information on Covid-19 aided participants in recognizing symptoms of the diseases.

The findings of this study highlight the need for the Government of Nigeria to adopt new strategies to improve psychological services at the community and individual levels, focussing on delivering accurate, evidence-based information to minimize the impact of fake news and identifying psychological interventions for promoting mental well-being across the country. As the Covid-19 outbreak is generally being controlled, our findings will be crucial in the establishment of a psychological support. If a massive epidemic arises, it is vital that healthcare systems and the general public be physically and psychologically prepared. Our findings have both clinical and policy relevance. First, based on sociodemographic data, health authorities must identify high-risk groups so that early psychological interventions can be performed. According to our sociodemographic statistics, the outbreak had the greatest psychological impact on self-employed and unemployed people, singles, and separated people. In the event of future outbreaks, the government should make arrangements for self-employed and unemployed people.

Secondly, health experts must assess the immediate psychological requirements of the general populace. Health practitioners should take advantage of the opportunity to give psychological support and interventions for patients who appear with or without symptoms of the diseases, especially during an outbreak, to alleviate anxiety and serious psychological difficulties. It is critical to obtain a family history and biodata, and health professionals should inquire about the level of concern for other family members, family members’ occupations, and marital status, especially for singles and unemployed people, as these concerns are linked to depression and anxiety, respectively.

Thirdly, the content of psychological therapy (for example, cognitive behavioural therapy [CBT]) should be modified to suit the needs of the general public during an epidemic. CBT should be available online or over the phone to prevent the transmission of infection. Because the presence of mental health specialists (such as psychologists) is not required for online CBT, it will assist the general public in Nigeria, where psychologists are in short supply. Behavioral therapy could focus on anxiety-relieving relaxation activities and activity scheduling to battle depression in the home environment (e.g., home-based exercise and entertainment).

The study’s cross-sectional measurement, which does not include longitudinal change observation, is a limitation of the study. More research with a larger group of people should be undertaken.


  Conclusions Top


During the early stages of the Covid-19 outbreak in Nigeria, nearly half of those polled were either normal or had borderline depression. Those who were self-employed or unemployed, single or separated were found to have a stronger psychological impact from the pandemic. The general public was well-informed and had access to specific, up-to-date, accurate health information as well as some precautionary actions. Our findings can be used to develop psychological interventions to increase mental health and psychological resilience.

Authors’ contribution

SOO conceived this article. Both SOO and OSJ were major contributors to development of study protocol, data collection, and data analysis. All authors contributed equally in writing the manuscript. All authors read and approved the final manuscript.

Financial support and sponsorship

Nil.

Conflicts of interest

The authors declare that they have no conflicts of interest.

Ethical approval

A written approval was obtained from the Ethics and Research Committee of the College of Health Sciences, Osun State University, Osogbo, Nigeria. The researchers were guided by the ethical principles for biomedical research as stated in the Declaration of Helsinki (World Medical Association, 2013).



 
  References Top

1.
Guo YR, Cao QD, Hong ZS, Tan YY, Chen SD, Jin HJ, et al. The origin, transmission and clinical therapies on coronavirus disease 2019 (COVID-19) outbreak—An update on the status. Mil Med Res 2020;7:11.  Back to cited text no. 1
    
2.
Anjorin AA, Odetokun IA, Abioye AI, Elnadi H, Umoren MV, Damaris BF, et al. Will Africans take COVID-19 vaccination? PLoS One 2021;16:e0260575.  Back to cited text no. 2
    
3.
Nigeria Centre for Disease Control. COVID-19 Nigeria Microsite [Internet]. Available from: https://covid19.ncdc.gov.ng/. [Last accessed on Mar 14, 2022].  Back to cited text no. 3
    
4.
Paules CI, Marston HD, Fauci AS Coronavirus infections—More than just the common cold. JAMA 2020;323:707-8.  Back to cited text no. 4
    
5.
Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020;395:497-506.  Back to cited text no. 5
    
6.
Rothe C, Schunk M, Sothmann P, Bretzel G, Froeschl G, Wallrauch C, et al. Transmission of 2019-nCoV infection from an asymptomatic contact in Germany. N Engl J Med 2020;382:970-1.  Back to cited text no. 6
    
7.
Chen N, Zhou M, Dong X, Qu J, Gong F, Han Y, et al. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: A descriptive study. Lancet 2020;395:507-13.  Back to cited text no. 7
    
8.
Impacts of COVID-19 Pandemic on Mental Health in Malaysia: A Single Thread of Hope | Shanmugam | Malay J Psychiatr [Internet]. Available from: https://mjpsychiatry.org/index.php/mjp/article/view/536. [Last accessed on Mar 14, 2022].  Back to cited text no. 8
    
9.
Holmes EA, O’Connor RC, Perry VH, Tracey I, Wessely S, Arseneault L, et al. Multidisciplinary research priorities for the COVID-19 pandemic: A call for action for mental health science. Lancet Psychiatry 2020;7:547-60.  Back to cited text no. 9
    
10.
Lu H, Nie P, Qian L Do quarantine experiences and attitudes towards COVID-19 affect the distribution of mental health in China? A quantile regression analysis. Appl Res Qual Life 2021;16:1925-42.  Back to cited text no. 10
    
11.
Chatterjee K, Chauhan VS Epidemics, quarantine and mental health. Med J Armed Forces India 2020;76:125-7.  Back to cited text no. 11
    
12.
Dubey S, Biswas P, Ghosh R, Chatterjee S, Dubey MJ, Chatterjee S, et al. Psychosocial impact of COVID-19. Diabetes Metab Syndr 2020;14:779-88.  Back to cited text no. 12
    
13.
Wang C, Riyu P, Xiaoyang W, Yilin T, Linkang X, Cyrus SH, et al. Immediate psychological responses and associated factors during the initial stage of the 2019 coronavirus disease (COVID-19) epidemic among the general population in China. Int J Environ Res Public Health 2020;17:1-25. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7084952/.  Back to cited text no. 13
    
14.
Sozański B, Ćwirlej-Sozańska A, Wiśniowska-Szurlej A, Jurek K, Górniak P, Górski K, et al. Psychological responses and associated factors during the initial stage of the coronavirus disease (COVID-19) epidemic among the adult population in Poland—A cross-sectional study. Available from: https://doi.org/10.1186/s12889-021-11962-8. [Last accessed on Mar 14, 2022].  Back to cited text no. 14
    
15.
Kang L, Ma S, Chen M, Yang J, Wang Y, Li R, et al. Impact on mental health and perceptions of psychological care among medical and nursing staff in Wuhan during the 2019 novel coronavirus disease outbreak: A cross-sectional study. Brain Behav Immun 2020;87:11-7.  Back to cited text no. 15
    
16.
Adesina M, Olufadewa I, Oladele R, Ayelawa S, Oladokun B, Ekerin B, et al. The impact of COVID-19 on the prevalence of anxiety disorders among Nigerians. Psychiatria 2022;19:11-7.  Back to cited text no. 16
    
17.
González-Sanguino C, Ausín B, Castellanos MÁ, Saiz J, López-Gómez A, Ugidos C, et al. Mental health consequences during the initial stage of the 2020 coronavirus pandemic (COVID-19) in Spain. Brain Behav Immun 2020;87:172-6. Available from: https://doi.org/10.1016/j.bbi.2020.05.040.  Back to cited text no. 17
    
18.
Pappa S, Ntella V, Giannakas T, Giannakoulis VG, Papoutsi E, Katsaounou P Prevalence of depression, anxiety, and insomnia among healthcare workers during the COVID-19 pandemic: A systematic review and meta-analysis. Brain Behav Immun 2020;88:901-7.  Back to cited text no. 18
    
19.
James Rubin G, Wessely S The psychological effects of quarantining a city. BMJ 2020;368:m313.  Back to cited text no. 19
    


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
Abstract
Introduction
Materials and Me...
Results
Discussion
Conclusions
References
Article Figures
Article Tables

 Article Access Statistics
    Viewed94    
    Printed0    
    Emailed0    
    PDF Downloaded20    
    Comments [Add]    

Recommend this journal