• Users Online: 73
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2021  |  Volume : 35  |  Issue : 2  |  Page : 44-49

Parent's perception and expectations from cochlear implants: Insights from a government-funded cochlear implants program in Kerala


Department of Audiology and Speech Language Pathology, National Institute of Speech and Hearing, Thiruvananthapuram, Kerala, India

Date of Submission03-May-2021
Date of Decision13-Jun-2021
Date of Acceptance13-Sep-2021
Date of Web Publication24-Dec-2021

Correspondence Address:
Sita Sreekumar
Department of Audiology and Speech Language Pathology, National Institute of Speech and Hearing, NISH Road, Sreekaryam, Thiruvananthapuram - 695 017, Kerala
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jisha.JISHA_13_21

Rights and Permissions
  Abstract 


Introduction: Parental perceptions and expectations are the key determinants for optimal outcomes from cochlear implants (CI). This article explores the parental perceptions and expectations of very young children who are prospective candidates for CI. Methods: The participants of this study were 97 parents (63 mothers; 34 fathers). They completed a 40-item questionnaire which reflected the parents expected outcomes on the domains communication and social skills, academic achievements, future life, rehabilitation demands, satisfaction, stress, and professional relations. The questionnaire was administered during a group counseling session conducted for prospective CI users under the government-funded CI program in Kerala, India. The responses were descriptively analyzed to present the results. Results: The results reveal that parents kept high expectations on communication abilities, intelligible speech, language abilities, telephone conversation, mainstream schooling, reading-writing abilities, and secure future life after their children receive cochlear implantation. Ninety-six percent of parents strongly agreed on parental involvement, intense, and prolonged therapy for maximal benefit. About 52.3% of parents were dissatisfied with the present communication and social skills of their children. About 33.3% of parents felt stressed about the rehabilitation process, whereas 78% viewed rehabilitation as their responsibility. Decision-making on CI was difficult for 48% of parents because of differing opinions among professionals. Conclusion: Understanding parental perceptions and expectations will help the service providers to impart holistic habilitation strategies after cochlear implantation. Further documenting parental perceptions is important to correlate the future experiences and outcomes from CI.

Keywords: Cochlear implants, hearing loss, parental expectations, parental perceptions


How to cite this article:
Sreekumar S, Joy JM. Parent's perception and expectations from cochlear implants: Insights from a government-funded cochlear implants program in Kerala. J Indian Speech Language Hearing Assoc 2021;35:44-9

How to cite this URL:
Sreekumar S, Joy JM. Parent's perception and expectations from cochlear implants: Insights from a government-funded cochlear implants program in Kerala. J Indian Speech Language Hearing Assoc [serial online] 2021 [cited 2022 Aug 12];35:44-9. Available from: https://www.jisha.org/text.asp?2021/35/2/44/333743




  Introduction Top


Technological advancements in the field of biomedical science have paved way for the development of better habilitation opportunities for individuals with severe-profound sensorineural hearing loss. Cochlear implants (CI) were one such invention that had the power to provide sense of hearing, and had tremendous impact on the rehabilitation of children with severe profound hearing loss.[1],[2] These children have shown to have significant positive outcomes in various areas of auditory, speech, language, academic, social, and communication development ever since its invention. Even though the outcomes from CI are influenced by many child-related and audiological factors, parents play a vital role in the decision-making process.

Early identification and intervention of hearing loss in children have influenced/fast tracked the availability of CI as early as possible in children receiving a diagnosis of bilateral profound hearing loss. This indeed makes the parents feel that they have limited time to decide on management.[3] Parents usually have high expectations about the outcomes from CI, but they often decide without any guarantee on the improvement their children will show after cochlear implantation.[4],[5],[6] Since CI are new, expensive, and high-tech, it ventures unrealistic expectations of being capable of bringing immediate changes in a child's auditory skills. This can limit the focus of parents on the postimplant re/habilitation process, which usually requires a long-term commitment.

Many variables need to be considered when evaluating young children for CI candidacy.[7],[8] There are standardized candidacy protocols which are being followed by the CI professionals before implantation, but some factors such as parental perception about hearing loss and their expectations from cochlear implantation are most often ignored. Researchers have predominantly used qualitative approaches such as interviews and open-ended questions to probe into parental perceptions, as they provide more information regarding the real-life situations.[9],[10],[11] There are only few questionnaires developed specifically for studying the perceptions and expectations from CI.[5],[6],[12],[13],[14],[15],[16]

A survey instrument developed by Zaidman-Zait and Most was used to study mothers' expectations regarding their children's cochlear implantation in Israel, focused on speech-related communication abilities, academic achievement, social skills, change in future life, and the rehabilitation process.[6] Mothers in this study had high expectations with respect to their children's communication, social, and academic abilities after cochlear implantation. Similar methods have been adopted to study parent's expectations from children using CI in North India and result revealed parents having high expectations on all the domains studied.[14]

Studies on the parental perceptions and expectations from cochlear implantation show that at younger ages, the process of informed decision-making is easier. Parents feel it important to have as much information as possible before implantation.[15] The process of imparting information and educating parents before surgery is often done by a team of professionals and is always multi-faceted.[17] The information given to parents should reflect the reality of experience, which is an insight for the professionals to apprehend how educational and informational processes provided before surgery change the parental perceptions and expectations.[15] The perceptions of parents considering decision-making and the process of implantation are that parents' needs and experiences were very varied and may not conform to the expectations of others, including implanting teams. The finding from this study thus urges professionals to be cautious when engaging parents in the process and emphasizes the need for professionals to have appropriate training in counseling and parent education. Sharing other parent's experiences, perceptions, expectations, and outcomes are probably helpful for naive parents considering CI for their children. Therefore, knowledge about the family values and aspirations for their child can help clinicians guide parents through the decision-making process. It was also shown that the amount of time families need to process the information and make a decision varies and that practitioners should support families and not rush the process. Parents desired more comprehensive and bias-free information to assist their decision-making. Studies have also shown that all outcome measures were positively associated with parental perceptions of a child's developmental status and their expectations.[14],[18]

In the recent past, the number of younger children getting implanted has increased in developing countries like India due to Government-funded schemes. Even though there has been plenty of research on outcomes on speech perception, speech and language developments, academic performances and enhanced quality of life in children with CI, very little inquiry has been done into the parental perception on deafness and expectations from CI in Indian scenario. It is important to impart a holistic habilitation process of which parental informed decision-making and involvement are key components for a successful outcome.[9],[19]

The purpose of this study was to explore the perceptions and expectations of parents of young children who were prospective CI users in Kerala. This would help the professionals in acknowledging the factors pertaining to parent's hopes regarding their child's outcome and empowering them with up-to-date information on the efficacy of CI, and setting the stage for realistic expectations.


  Materials and Methods Top


Participants

Parents (63 mothers and 34 fathers) of 97 children who were prospective candidates for cochlear implantation were the participants of this study. The mean age of 97 children was 32.96 months (range = 12–60 months). All children were diagnosed with severe-profound hearing loss (with no comorbidities and structural malformations of the ear). They were fitted with hearing aids and attended at least three months of intervention before cochlear implantation. The mean age of 63 mothers was 27.86 years and that of fathers was 35.38 years. These parents were recruited from a group counseling session, which is carried out as a standard protocol as part of the Sruthitharangam Cochlear Implantation Program (SCIP), the government-funded CI program in Kerala, India.

Background information about Sruthitharangam Cochlear Implantation Program

SCIP is a government-funded program in the state of Kerala which provides one CI free of cost for children with severe to profound sensorineural hearing loss under 5 years of age. The auditory-verbal intervention for 2 years is also supported under the project. A preimplant evaluation is carried out by the team of professionals for determining the candidacy for cochlear implantation, which includes audiological test battery, speech and language evaluation, psychological evaluation, radiological evaluation, and medical examination. The parents of children thus selected for CI were called for a group counseling session to educate them on the importance of intensive speech and language intervention, care and maintenance of the speech processor, surgical procedures, implant switch on, and other related audiological procedures. The data for the present study were accumulated over three such group counseling sessions. All parents were native Malayalam speakers.

Material used

The items were selected from the Parents Expectations Questionnaire for CI developed by Zaidman-Zait and Most, 2005. These items were translated into Malayalam and reverse translation was done to ensure consistency in meaning. Then, a native Malayalam speaker who had language proficiency in both English and Malayalam proofread the questions made in Malayalam. A few questions regarding academic achievement and communication domains that were found to have similar meanings were omitted. The details of the questionnaire used to elicit the parental perceptions and expectations are shown in [Table 1]. The parents were asked to rate their level of agreement for each question with a 4-point Likert scale (1–4) which ranged from strongly disagree to strongly agree.
Table 1: Domains and items in the questionnaire

Click here to view


Procedure

Clearance was obtained from the ethical committee of the National Institute of Speech and Hearing. A written consent was obtained from all the participants. All the parents were given the questionnaires in a printed format after the group counseling session and instructions regarding completing the questionnaire and rating the responses were provided by the researchers.

Descriptive statistical analysis was performed using the IBM SPSS Statistics for Windows (Version 22.0. Armonk, NY: IBM Corp.) and relevant interpretations were drawn.


  Results Top


The results are represented in terms of the parent's perception and expectation from CI. The subsequent tables from [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7] show the “agree” and “strongly agree” responses reported by parents for the different questions elicited under each domain studied. In all domains, there was negligible “strongly disagree” and “disagree” responses except for stress.
Table 2: Parent's response to questions related to stress

Click here to view
Table 3: Parent's response to questions on expectation on communication skills after cochlear implantation

Click here to view
Table 4: Parent's response to questions on expectation on academic achievements after cochlear implantation

Click here to view
Table 5: Parent's response to questions on expectation on future life after cochlear implantation

Click here to view
Table 6: Parent's response to questions on expectation on social skills after cochlear implantation

Click here to view
Table 7: Parent's response to questions on expectation on rehabilitation demands after cochlear implantation

Click here to view


Parental perception on deafness

Parent's perception of their child's hearing loss was elicited on four domains, namely the parent's role in habilitation, satisfaction over the present communication and social skills in their child, stress level felt by the parents, and satisfaction with the present habilitation services. About 97% of them understood the importance of parents' role in habilitation, 42.2% of parents were satisfied with the present communication and social skills of their children, and 38.75% of parents were satisfied with habilitation services. The percentage of parents who responded to the domain of stress is depicted in [Table 2]. However, all parents did not respond to question number 3 (2.13%), 7 (1.06%), and 8 (2.13%), respectively.

Parental expectations from cochlear implants

Parent's expectations on the child's development after cochlear implantation on various aspects have been categorized into communication skills, academic achievements, future life, social skills, and rehabilitation demands. The degree of agreement (agree and strongly agree responses) for different questions elicited under these domains are described below. “Strongly disagree” and “disagree” responses have not been shown as there were negligible responses.

Communication skills

Parents had high expectations regarding their child's ability to communicate easily with his/her family members (94.38%), ability to easily participate in social conversations (97.90%), improve his/her language skills tremendously (97.70%) and develop intelligible speech (96.90%) [Table 3]. They also believed that their children would be able to understand speech without relying on lip reading (95.90%), able to detect even very quiet sounds in his/her environment like whispers (92.80%), use the telephone (94.80%), and will not have the requirement to use sign language (88.70%).

Academic achievements

Parents had high expectations that their children will improve in their learning abilities (97.90%), be able to participate in regular classroom settings (96.95%), and achieve high standards in reading and writing (97.45%) [Table 4].

Future skills

Parents anticipate that a CI will change their child's future (98%) and that their children will acquire normal hearing (95.90%), will have dramatic change in life and function like a child with typical hearing (97%) [Table 5].

Social skills

Parents also foresee that their children will be able to make friends with hearing peers (97.90%) and will be accepted in classrooms due to improved social skills (95.90%) [Table 6].

Rehabilitation demands

Parents believed that their children need to participate in intensive listening training (96.93%), and may not require prolonged speech training like children who use conventional hearing aids (81.30%). They also anticipate that they will have to put in lot of effort into the rehabilitation process (98%) and schedule their time to work with their kids (94.80%) [Table 7].


  Discussion Top


Parental perception on deafness

The questions addressing parent's perception on hearing loss provided insight into beliefs and difficulties related to their children's hearing loss. Ninety-seven percent of parents strongly agreed to the fact that for a successful outcome, there was a need for long-term parental involvement, intense and prolonged therapy.[20],[21] The prerequisite for applying for the SCIP requires bilateral hearing aid fitting and intervention for at least 3 months. Hence, the parents were aware about the significance of intensive rehabilitation. This preimplant habilitation has equipped the parents regarding the same. However, only 42.2% of parents were satisfied with the present communication and social skills of their children; even though they expect higher skills after cochlear implantation.[22] All the children in this study received the diagnosis of bilateral severe-profound hearing loss and had a history of preimplant speech-language intervention for at least 3 months duration with digital hearing aids in both ears. However, their speech and language development were poor. Their preimplant speech perception abilities with hearing aids tested using aided audiograms were out of the speech spectrum in preimplant evaluations. Significantly, lower language scores are obtained in children with severe-profound hearing loss using hearing aids, and it is shown that acceleration of language development is possible with CI if they have the better preimplant residual hearing.[23] It was quite interesting to note that 63.30% of parents did not face any stress-related issues as many studies in the literature report high-stress levels in parents of children with hearing loss. The preimplant period of intervention has made the parents settle down with respect to their psychosocial aspects and accept the hearing loss in their children and work toward achieving spoken language outcomes. About 82.98% of them did not have any family arguments related to their child's hearing loss, 72.34% of them did not regret the extra time spent for their kids, and 77.66% of them never considered their children with hearing loss being a burden for them. About 71.28% of them never left hope behind for their child.

Only 36.04% of parents reported stress due to factors such as extra time being devoted to the problems of hearing impairment, child's behavior being a source of worry, more family arguments related to child with hearing impairment, losing hopes and dreams related to the child due to the presence hearing impairment, not having time for themselves, and they consider it as their responsibility alone which creates a sense of burden. The high degree of parental stress, greater period of grief and adjustment has been shown in parents of children with hearing impairment as compared with parents of hearing children.[12],[24],[25] A better understanding of stress in parents, especially mothers may result in the provision of improved services for families at both the family and organizational levels.[26],[27] Implementation of counseling sessions by professionals, parent support groups, interaction with parents with similar experiences, and support from counselors or psychologists can reduce the stress and anxiety of parents.[14]

Some parents (38.75%) reported dissatisfaction on the current rehabilitation service delivery due to factors such as the professional approach being less satisfactory toward children and their parents and differing opinions among professionals regarding the management strategies.[13] These findings highlight the need for a structured protocol to be developed among the CI professionals to provide unbiased information about the support services.[28] An informative and all-encompassing preimplant counseling and assessment protocol with the family will help in informed decision-making.[15] This will also help parents to develop realistic expectations from CI.

Parental expectations from cochlear implants

Overall, the parents have shown high expectations on all the domains studied. 94.38% of parent's responses to questions related to communication abilities revealed high expectations after CI. Furthermore, 97.9% and 96.9% of parents expected tremendous improvements in language and speech abilities, respectively. A study by Nikolopoulos et al.[5] showed that the role of CI surpassed parental expectations in the domains of communication, speech-language development, and listening skills. Similarly, in a study by Stefanini et al.[22] expectations were high in domains of communication, leading to better social relations and the development of autonomy. About 94.8% of parents were confident that their children will be able to carry out telephonic conversations. The questions related to academic achievements revealed that 96.95% of parents expected their children to cope up with mainstream schooling and 97.45% of parents have high expectation on achieving high standards in reading and writing skills. About 96.97% of parents expect their children to function like other children with typical hearing with CI bringing dramatic changes in their future lives. Parents have also shown high expectations of tremendous improvements in social skills (97.4%). The parents have great hope on the implant that it will enable their child to function in the hearing world eventhough the outcomes from CI are highly individualistic.[10] Parents of children using CI agree that their children can join regular schools and schools fulfilling their needs.[22] Social skills and participations have been reported to improve in terms of good relationships with siblings, elders and peers, ability to making friendships, active participation in activities with other children.[28]

96.93% of parents showed improved awareness about the need and importance of long-term intensive rehabilitation needed for positive outcomes in their child and they believe that parents play an important role in this success. Similar findings have been reported by Kumar et al.[14] that parents are aware about the importance of intensive speech, language, and listening training which will help the clinicians to provide parents a better understanding of home training. However, the outcomes were highly individualistic, even though the expectations of parents about their child after implantation was to function with the hearing peers. The results from the present study reiterate the evidence that although the beliefs and experiences related to their children's hearing loss vary among parents, they had high expectations from CI, specifically to develop speech, language, communication, and social skills. This information will also help clinicians working with families of children with hearing loss to identify the specific areas that need to be worked intensively to meet the demands of parental expectations.


  Conclusion Top


This study findings proposes professionals to address parent's aspirations, values, and expectations regarding the success of the child while imparting information regarding management strategies. A holistic approach toward habilitation will be the key for successful outcomes in children with CI. The reality of experience is determined by the parent's expectations along with the quality of information and guidance provided to them. Further, documentation of parental perceptions is important to correlate the future experiences and outcomes from CI.

Limitations and future directions

The other factors (such as socioeconomic, service delivery, psychosocial aspects) that can have an effect on the parental perceptions and expectations were not probed into. A correlation of these factors and the parental responses would point out to the relationships among factors. Using a mixed-method and incorporating a qualitative method of data collection would have added light onto several aspects. Future studies are warranted to understand the relationship between the expectations and experience of these parents.

Acknowledgment

We acknowledge the contributions by Dr Ashraf T P, former executive director, Kerala Social Security mission (KSSM), Government of Kerala for reviewing the items used in the questionnaire. We acknowledge the support extended by KSSM for the smooth conduct of group counselling sessions.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Geers AE. Spoken language in children with cochlear implants. In P. E. Spencer & M. Marschark (Eds.), Advances in the spoken language development of deaf and hard-of-hearing children. Oxford University Press; 2005; p 244-70.  Back to cited text no. 1
    
2.
Kirk K, Hudgins M. Speech perception and spoken word recognition in children with cochlear implants. In N. M. Young, & K. I. Kirk (Eds.), Pediatric Cochlear Implantation: Learning and the Brain . Springer.2016; p 145-61.  Back to cited text no. 2
    
3.
Hyde M, Punch R, Komesaroff L. Coming to a decision about cochlear implantation: Parents making choices for their deaf children. J Deaf Stud Deaf Educ 2010;15:162-78.  Back to cited text no. 3
    
4.
Christiansen JB, Leigh IW. Children with cochlear implants changing parent and deaf community perspectives. Arch Otolaryngol Head Neck Surg 2004 130:673-7.  Back to cited text no. 4
    
5.
Nikolopoulos TP, Lloyd H, Archbold S. Pediatric cochlear implantation the parents' perspective. Arch Otolaryngol Head Neck Surg 2001;127:363-7.  Back to cited text no. 5
    
6.
Zaidman-Zait A, Most T. Cochlear implants in children with hearing loss: Maternal expectations and impact on the family. Volta Rev 2005;105:129-50.  Back to cited text no. 6
    
7.
Franck KH, Mishra A. Pediatric cochlear implantation-I: Candidacy. Indian J Otolaryngol Head Neck Surg 2003;55:137-42.  Back to cited text no. 7
    
8.
Maggs J, Ambler M, Hanvey K. Trends in cochlear implant candidacy in children. Paediatr Child Health (United Kingdom) 2017;27:454-8.  Back to cited text no. 8
    
9.
Li Y, Bain L, Steinberg AG. Parental decision-making in considering cochlear implant technology for a deaf child. Int J Pediatr Otorhinolaryngol 2004;68:1027-38.  Back to cited text no. 9
    
10.
Sach TH, Whynes DK. Paediatric cochlear implantation: The views of parents. Int J Audiol 2005;44:400-7.  Back to cited text no. 10
    
11.
Kluwin TN, Stewart DA. Cochlear implants for younger children: A preliminary description of the parental desicion progress and outcomes. Am Ann Deaf 2000;145:26-32.  Back to cited text no. 11
    
12.
Alam MN, Munjal S, Sharma A, Panda N, Banumathy N. Parental expectation and perception of CI benefits in their implanted wards. Indian J Otolaryngol Head Neck Surg 2019;71:1153-6.  Back to cited text no. 12
    
13.
Dev AN, Lohith U, Pascal B, Dutt CS, Dutt SN. A questionnaire-based analysis of parental perspectives on pediatric cochlear implant (CI) re/habilitation services: A pilot study from a developing CI service in India. Cochlear Implants Int 2018;19:338-49.  Back to cited text no. 13
    
14.
Kumar P, Sanju HK, Mishra R, Singh V, Mohan P. Parental expectation from children with cochlear implants in Indian context: A questionnaire based study. Int Arch Otorhinolaryngol 2017;21:156-60.  Back to cited text no. 14
    
15.
Archbold S, Sach T, O'Neill C, Lutman M, Gregory S. Deciding to have a cochlear implant and subsequent after-care: Parental perspectives. Deaf Educ Int 2006;8:190-206.  Back to cited text no. 15
    
16.
O'Neill C, Lutman ME, Archbold SM, Gregory S, Nikolopoulos TP. Parents and their cochlear implanted child: Questionnaire development to assess parental views and experiences. Int J Pediatr Otorhinolaryngol 2004;68:149-60.  Back to cited text no. 16
    
17.
Alkhamra RA. Cochlear implants in children implanted in Jordan: A parental overview. Int J Pediatr Otorhinolaryngol 2015;79:1049-54.  Back to cited text no. 17
    
18.
Lin FR, Wang NY, Fink NE, Quittner AL, Eisenberg LS, Tobey EA, et al. Assessing the use of speech and language measures in relation to parental perceptions of development after early cochlear implantation. Otol Neurotol 2008;29:208-13.  Back to cited text no. 18
    
19.
Duncan J. Parental readiness for cochlear implant decision-making. Cochlear Implants Int 2009;10 Suppl 1:38-42.  Back to cited text no. 19
    
20.
Incesulu A, Vural M, Erkam U. Children with cochlear implants: Parental perspective. Otol Neurotol 2003;24:605-11.  Back to cited text no. 20
    
21.
Bhamjee A, Roux TL, Schlemmer K, Perold J, Cass N, Schroeder K, et al. Parent-perceived challenges related to the pediatric cochlear implantation process and support services received in South Africa. Int J Pediatr Otorhinolaryngol 2019;126:109635.  Back to cited text no. 21
    
22.
Stefanini MR, Morettin M, Zabeu JS, Bevilacqua MC, Moret AL. Parental perspectives of children using cochlear implant. Codas 2014;26:487-93.  Back to cited text no. 22
    
23.
Yoshinaga-Itano C, Baca RL, Sedey AL. Describing the trajectory of language development in the presence of severe-to-profound hearing loss: A closer look at children with cochlear implants versus hearing aids. Otol Neurotol 2010;31:1268-74.  Back to cited text no. 23
    
24.
QuittnerAL, Steck JT, Rouiller RL. Cochlear implants in children: A study of parental stress and adjustment. Am J Otol 1991; Supplementary number 12:95104.  Back to cited text no. 24
    
25.
Sarant J, Garrard P. Parenting stress in parents of children with cochlear implants: Relationships among parent stress, child language, and unilateral versus bilateral implants. J Deaf Stud Deaf Educ 2014;19:85-106.  Back to cited text no. 25
    
26.
Macker, Julie, “Childhood Hearing Loss and its Stress on Hearing Families”. Walden Dissertations and Doctoral Studies. 2015; 1413. Available at https://scholarworks.waldenu.edu/cgi/viewcontent.cgi?article=2412&context=dissertations. [Last accessed on 2021 Feb 05].  Back to cited text no. 26
    
27.
Majorano M, Guerzoni L, Cuda D, Morelli M. Mothers' emotional experiences related to their child's diagnosis of deafness and cochlear implant surgery: Parenting stress and child's language development. Int J Pediatr Otorhinolaryngol 2020;130:109812.  Back to cited text no. 27
    
28.
Singh U, Kapasi A, Patel N, Khandhar V, Neupane AK. Expectations and experience of children with unilateral cochlear implantation: A parental perspective. Indian J Otolaryngol Head Neck Surg 2019;71:442-8.  Back to cited text no. 28
    



 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]



 

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
Conclusion
References
Article Tables

 Article Access Statistics
    Viewed1399    
    Printed70    
    Emailed0    
    PDF Downloaded189    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]