BMC Health Services Research - Full Text - Record Linkage Research and Informed Consent: Who Consents? PDF

21/10/14 17:06 BMC Health Services Researcrmed consent: who consents?
Pgina 1 de 14 http://www.biomedcentral.com/1472-6963/7/18
1.66
Abstract
Background
Research article
Record linkage research and informed consent: who consents?
Nicole Huang
1
, Shu-Fang Shih
2
, Hsing-Yi Chang
2
and Yiing-Jenq Chou
1*
BMC Health Services Research 2007, 7:18 doi:10.1186/1472-6963-7-18
The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1472-6963/7/18
Received: 24 August 2006
Accepted: 12 February 2007
Published: 12 February 2007
2007 Huang et al; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Corresponding author: Yiing-Jenq Chou
Institute of Public Health, School of Medicine, National Yang-Ming University, No. 155, Section 2, Li-Nong Street, Taipei 112, Taiwan, R.O.C
Center for Health Policy Research and Development, National Health Research Institutes, No. 35, Keyan Road, Zhunan Town, Miaoli County 350, Taiwan, R.O.C
For all author emails, please log on.
* yjchou@ym.edu.tw
1
2
Record linkage research and informed consent: who consents?
http://www.biomedcentral.com/1472-6963/7/18
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Institute of Public Health, School of Medicine, National Yang-Ming University, No. 155, Section 2, Li-Nong Street, Taipei 112, Taiwan, R.O.C
Center for Health Policy Research and Development, National Health Research Institutes, No. 35, Keyan Road, Zhunan Town, Miaoli County 350, Taiwan, R.O.C
Background
Linking computerized health insurance records with routinely collected survey data is becoming increasingly popular in health services research. However, if consent
not universal, the requirement of written informed consent may introduce a number of research biases. The participants of a national health survey in Taiwan were asked
to have their questionnaire results linked to their national health insurance records. This study compares those who consented with those who refused.
Methods
A national representative sample (n = 14,611 adults) of the general adult population
Survey (NHIS) and who provided complete survey information were used in this study. At the
permission to access their National Health Insurance records. Information given by the interviewees in
linkage and who wasn't.
Results
Of the 14,611 NHIS participants, 12,911 (88%) gave consent, and 1,700 (12%) denied
area residents were significantly more likely to deny consent. The aborigines were significantly less likely to refuse. No discrepancy in gender and self-reported health
was found between individuals who consented and those who refused.
Conclusion
This study is the first population-based study in assessing the consent pattern in a general Asian population. Consistent with people in Western societies, in Taiwan,
typical Asian society, a high percentage of adults gave consent for their health insurance records and questionnaire results to be linked. Consenters differed significantly
from non-consenters in important aspects such as age, ethnicity, and educational background.
the possibility of selection bias. Researchers should take this source of bias into consideration
bias on their results.
Background
Linking computerized health insurance records with routinely collected survey data is becoming increasingly popular in health services research. Record linkage serves
a powerful tool to augment and validate the data acquired for research. Inevitably, the growing number of record linkage studies have created a serious public concern
regarding the privacy of personal information, and has led many governments to institute
consent is not universal, the requirement of written informed consent may introduce a number of research biases. Most importantly, seeking individual informed
may lead to serious selection bias, and may compromise the external validity of the research if the consent pattern is not uniform. Furthermore, since not everyone
interviewed in surveys gives consent to access their health records, the sample size needs to be increased to compensate for those that do not consent.
Only a few studies have examined patterns of consent in relation to linkage of survey
indicate that consent is not universal, and that factors such as age [2-5,8], gender [2
is becoming increasingly popular in health services research. However, if consent is
of research biases. The participants of a national health survey in Taiwan were asked
This study compares those who consented with those who refused.
A national representative sample (n = 14,611 adults) of the general adult population aged 20 years or older who participated in the Taiwan National Health Interview
(NHIS) and who provided complete survey information were used in this study. At the end of the survey, the respondents were asked if they would give
their National Health Insurance records. Information given by the interviewees in the survey was used to analyze who was more likely to consent to
Of the 14,611 NHIS participants, 12,911 (88%) gave consent, and 1,700 (12%) denied consent. The elderly, the illiterate, those with a lower income, and the suburban
significantly less likely to refuse. No discrepancy in gender and self-reported health
a general Asian population. Consistent with people in Western societies, in Taiwan, a
insurance records and questionnaire results to be linked. Consenters differed significantly
from non-consenters in important aspects such as age, ethnicity, and educational background. Consequently, having a high consent rate (88%) may not fully eliminate
of selection bias. Researchers should take this source of bias into consideration in their study design and investigate any potential impact of this source of
is becoming increasingly popular in health services research. Record linkage serves as
the growing number of record linkage studies have created a serious public concern
regarding the privacy of personal information, and has led many governments to institute a mandatory informed consent for access to health records [1]. However, if
may introduce a number of research biases. Most importantly, seeking individual informed consent
of the research if the consent pattern is not uniform. Furthermore, since not everyone
needs to be increased to compensate for those that do not consent.
Only a few studies have examined patterns of consent in relation to linkage of survey data with medical or administrative records [2-8]. The findings of these studies
2,3], health status [2-4,6-8], socioeconomic status [4-7], and ethnicity [5] may have
influenced consent to record linkage. However, the direction of the relationship between these factors and the giving of consent remains inconclusive. For example,
studies conducted in the USA [3,8], and Australia [4] suggest that older people are more likely to give consent, while studies in the UK
still others [6] show no influence. These variations in data may be owing to differences in study
part, limited to patients with a particular disease, specific demographic sub-populations (mostly
this important issue for a general population in an Asian country, even though record linkage studies
health research. Due to cultural heterogeneity regarding confidentiality and privacy issues, the experiences
populations. This study aimed to explore how, in Taiwan, a newly developed Asian country with rich data resources,
consent differ in important aspects from those who decline.
Methods
In 2001, the National Health Research Institutes (NHRI) in Taiwan conducted the National
systematic sampling design based on the degree of urbanization, geographic location, and administrative
design and sampling scheme have been reported elsewhere [9]. The consent rate of the original health survey was 94.2% and the demographic characteristics
sample were consistent with the population [9]. In this survey, a national representative sample of 22,121 people aged 12 years
purpose of this study, we only included those 15,413 survey respondents with a valid 10-digit personal identification (ID) number and who
Like the social security number in the United States, each resident in Taiwan has a personal ID number that is provided by the government.
some personal ID numbers might have been miscoded or missing. Only those ID numbers which were not missing and were consistent with the official
personal ID assignment were considered "valid" identification numbers.
At the end of the NHIS survey, the participants were asked for permission to access their National Health Insurance (NHI) records for research purposes. The NHI
program is a mandatory national health insurance program which provides comprehensive medical
rate is above 99%. This comprehensive benefits package includes preventive care, ambulatory care
services, Chinese medicine services, and prescription drugs. The NHI claims data contains a
service, diagnoses, procedures, drugs prescribed, reimbursements, hospital and physician identifiers.
consent form. In addition to the question on consent, the answers, to a large range of other survey
factors related to this consent. The survey variables considered in this study include demographics
socio-economic status (education, household income), and health status (the 8 health domains from
functioning, role limitation-physical, role limitation-emotional, mental health, social functioning,
better health or functioning.
Both simple and multiple logistic regression models were used. First, a series of simple logistic models were fitted separately for each factor. Then, a multiple logistic
model was used to relate the adjusted odds of consent with all demographics, socioeconomic
9.0 and STATA 8.0 statistical software packages.
between these factors and the giving of consent remains inconclusive. For example,
] suggest that older people are more likely to give consent, while studies in the UK [2,5] suggest the opposite, and
] show no influence. These variations in data may be owing to differences in study design and the target population. Previous researches are, for the most
to patients with a particular disease, specific demographic sub-populations (mostly the elderly or women), or to Western countries. No one has investigated
issue for a general population in an Asian country, even though record linkage studies conducted in Asia play an increasingly important role in medical and
Due to cultural heterogeneity regarding confidentiality and privacy issues, the experiences in western countries may not be generalizable to Asian
to explore how, in Taiwan, a newly developed Asian country with rich data resources, individuals in the general adult population who
In 2001, the National Health Research Institutes (NHRI) in Taiwan conducted the National Health Interview Survey (NHIS). The NHRI used a multistage stratified
design based on the degree of urbanization, geographic location, and administrative boundaries to select a representative sample. Details of the
]. The consent rate of the original health survey was 94.2% and the demographic characteristics of this
]. In this survey, a national representative sample of 22,121 people aged 12 years and older was interviewed. For the
survey respondents with a valid 10-digit personal identification (ID) number and who were aged 20 years or older.
each resident in Taiwan has a personal ID number that is provided by the government. During the survey process,
Only those ID numbers which were not missing and were consistent with the official algorithm of
their National Health Insurance (NHI) records for research purposes. The NHI
is a mandatory national health insurance program which provides comprehensive medical care coverage to all civilian Taiwanese residents, and the enrollment
99%. This comprehensive benefits package includes preventive care, ambulatory care in both clinic and hospital settings, inpatient hospital services, dental
Chinese medicine services, and prescription drugs. The NHI claims data contains a government assigned personal ID number, gender, date of birth, date of the
diagnoses, procedures, drugs prescribed, reimbursements, hospital and physician identifiers. Those participants that consented to linkage were asked to sign a
addition to the question on consent, the answers, to a large range of other survey questions provided by these participants allowed us to identify the
to this consent. The survey variables considered in this study include demographics (age, gender, marital status, ethnicity, urbanization of residence),
status (education, household income), and health status (the 8 health domains from the 36-Item Short-Form Health Survey Taiwan version 1.0-physical
limitation-physical, role limitation-emotional, mental health, social functioning, bodily pain, vitality, general health). A higher domain score reflects
simple logistic models were fitted separately for each factor. Then, a multiple logistic
model was used to relate the adjusted odds of consent with all demographics, socioeconomic status, and health status variables. All analyses were conducted using SAS
Results and discussions
Of the 15,413 individuals with a valid ID, 802 interviewees with incomplete survey information were excluded. Of the 802 that were excluded, 74% had given consent.
The remaining sample of 14,611 individuals was used for analyses. Of the 14,611 NHIS participants,
records, and 1,700 (12%) denied consent (Table 1). A high percentage of participants gave consent to link their health insurance records
Non-consent was the highest among those aged 65 or older, who were married, illiterate, those with a monthly household income < 30,000
were living in a suburban area. Non-consenters had relatively lower mean scores in all eight physical and mental functional status domains of SF-36.
distributions presented in the Table 1, the consent rates appeared to differ for all characteristics, except for gender.
Table 1. Characteristics of study sample
More specifically, Table 2 reports the main results of both the simple and the multiple logistic regression
marital status, ethnicity, education, household income, urbanization and functional status were significant
factors, the multiple logistic regression analysis showed a dose-response between non-consent and increased age,
other hand, after adjusting for age, gender, household income, and functional status, the minority ethnic group in Taiwan (Taiwan aborigines) was 77% less likely
refuse than the majority ethnic group (Fujianese). Although the observations for ethnic minorities as reported by other studies in the USA and the UK were either not
different from the general population [3,6] or more likely [5] to refuse consent, we observed the opposite in Taiwan. This is possibly due to the
or a lower suspicion of health research. In terms of socioeconomic status (SES), we found that, consistent with other studies
likely to be illiterate (odds ratio = 1.52, 95% confidence interval = 1.191.94), and with monthly household income lower than $NT
confidence interval = 1.041.49). Also, individuals living in suburban areas (odds ratio = 1.45, 95% confidence interval = 1.271.65)
refuse consent compared to those living in urban areas. Most importantly, contrary to other studies in the USA
physical and mental health did not have a strong influence on giving consent or on refusing consent among Taiwanese adults. Out of the eight
only the vitality domain showed a marginally significant influence on non-consent (odds ratio = 0.91; 95% confidence interval = 0.880.95).
Table 2. Factors associated with refusing consent to link questionnaire with health insurance
Conclusion
This study is the first population-based study in assessing the consent patterns in a general Asian population. The unique nature of the NHIS allowed us to investigate
important characteristics influencing non-consent in a large group of Asian adults who agreed to participate in a national health survey. Our study findings yield
important implications for researchers linking survey data to health insurance records in an
countries to give consent to linkage. The consent rate (88%) observed in a general Taiwanese
observed in Western countries such the USA, the UK, and Australia. Although the consent rate
information were excluded. Of the 802 that were excluded, 74% had given consent.
remaining sample of 14,611 individuals was used for analyses. Of the 14,611 NHIS participants, 12,911 (88%) gave consent to link their questionnaire to their NHI
). A high percentage of participants gave consent to link their health insurance records to their questionnaire results.
older, who were married, illiterate, those with a monthly household income < 30,000 New Taiwan (NT) dollars, or
lower mean scores in all eight physical and mental functional status domains of SF-36. Based on the
, the consent rates appeared to differ for all characteristics, except for gender.
reports the main results of both the simple and the multiple logistic regression analyses. The bivariate results indicate that factors such as age,
ethnicity, education, household income, urbanization and functional status were significant predictors of non-consent. But, after adjusting for other
regression analysis showed a dose-response between non-consent and increased age, which is consistent with other studies [2,5,8]. On the
status, the minority ethnic group in Taiwan (Taiwan aborigines) was 77% less likely to
ethnic minorities as reported by other studies in the USA and the UK were either not
] to refuse consent, we observed the opposite in Taiwan. This is possibly due to the heterogeneity in culture
status (SES), we found that, consistent with other studies [4-7] those refusing consent were more
confidence interval = 1.191.94), and with monthly household income lower than $NT 30,000 (odds ratio = 1.24, 95%
living in suburban areas (odds ratio = 1.45, 95% confidence interval = 1.271.65) were significantly more likely to
areas. Most importantly, contrary to other studies in the USA [2,8], the UK [3], and Australia [4], in the present study
on giving consent or on refusing consent among Taiwanese adults. Out of the eight SF-36 health domains,
on non-consent (odds ratio = 0.91; 95% confidence interval = 0.880.95).
Factors associated with refusing consent to link questionnaire with health insurance records
a general Asian population. The unique nature of the NHIS allowed us to investigate
who agreed to participate in a national health survey. Our study findings yield
implications for researchers linking survey data to health insurance records in an Asian population. First, people in Taiwan are as likely as people in Western
to give consent to linkage. The consent rate (88%) observed in a general Taiwanese population, a typical Asian population, is within the range of consent rates
in Western countries such the USA, the UK, and Australia. Although the consent rate is high for record linkage studies, non-consent still adds data attrition on
1. Tu JV, Willison DJ, Silver FL, Fang J, Richards JA, Laupacis A, Kapral MK, Investigators in the Registry of the Canadian Stroke Network:
Informed Consent in the Registry of the Canadian Stroke Network.
top of that attributable to non-response of the original survey. Hence, it must be taken
Second, contrary to the findings in Western countries, in Taiwan we did not find any discrepancy in gender and self-reported health between individuals who consented
and those that refused. Also, whereas ethnic minorities in the UK or the USA were less
aborigines in Taiwan showed the opposite. This study illustrates the need to investigate consent
Finally, in Taiwan, a typical Asian society, consenters differed significantly from non-consenters in important aspects such as age, education and income level. One
plausible explanation is that some of the elderly, illiterate or lower-income participants may
between them and interviewers. As the non-uniform consent distribution of these variables
research restricted to consenters may encounter the risk of miss-characterizing the utilization
bias. With other words, having a high consent rate (88%) will not necessarily guarantee full
participate in a record linkage study of this nature, researchers need to increase sample sizes
of bias using sensitivity analyses. Also, in order to minimize the potential source of bias
the proportion of participants consenting to linkage of health insurance records in surveys.
Competing interests
The author(s) declare that they have no competing interests.
Authors' contributions
NH and YJC were involved in all aspects of this study including conceptualization, analyses, interpretations, and writing of the article. SFS helped to perform the
statistical analyses and interpretation of the results. HYC was involved in data collection, analyses
final manuscript.
Acknowledgements
This research was supported by the National Science Council of Taiwan, R.O.C. (NSC
090-PP-01, HP-091-PP-01, BS-090-PP-04, BS-091-PP-04) and the Bureau of Health Promotion, Department
References
Kapral MK, Investigators in the Registry of the Canadian Stroke Network: Impracticability of
that attributable to non-response of the original survey. Hence, it must be taken into consideration in the initial sample size calculation [2,3,5,6].
discrepancy in gender and self-reported health between individuals who consented
those that refused. Also, whereas ethnic minorities in the UK or the USA were less likely to give consent or there was no difference compared to others, the
in Taiwan showed the opposite. This study illustrates the need to investigate consent patterns in populations with different cultural backgrounds.
non-consenters in important aspects such as age, education and income level. One
explanation is that some of the elderly, illiterate or lower-income participants may be hesitant to give consent due to ineffective communications or lack of trust
them and interviewers. As the non-uniform consent distribution of these variables may be significantly related to utilization and health outcomes, record linkage
restricted to consenters may encounter the risk of miss-characterizing the utilization and health outcomes of the general population and thus lead to selection
other words, having a high consent rate (88%) will not necessarily guarantee full elimination of possible selection bias. As one expects some refusal to
in a record linkage study of this nature, researchers need to increase sample sizes to account for non-consenters, and they must investigate potential effects
using sensitivity analyses. Also, in order to minimize the potential source of bias mentioned in this study, more work is needed to explore strategies for increasing
surveys.
analyses, interpretations, and writing of the article. SFS helped to perform the
analyses and interpretation of the results. HYC was involved in data collection, analyses and interpretation of the results. All authors read and approved the
This research was supported by the National Science Council of Taiwan, R.O.C. (NSC 94-2314-B-010-063), the National Health Research Institutes (Project Number: HP-
HP-091-PP-01, BS-090-PP-04, BS-091-PP-04) and the Bureau of Health Promotion, Department of Health in Taiwan.
Informed Consent in the Registry of the Canadian Stroke Network.
N Engl J Med 2004, 350:1414-1421. PubMed Abstract | Publisher Full Text
2. Dunn KM, Jordan K, Lacey RJ, Shapley M, Jinks C: Patterns of consent in epidemiologic research: Evidence from over 25,000 responders.
Am J Epidemiol 2004, 159:1087-1094. PubMed Abstract | Publisher Full Text
3. Woolf SH, Rothemich SF, Johnson RE, Marsland DW: Selection bias from requiring patients to give consent to examine data for health
Arch Fam Med 2000, 9:1111-1118. PubMed Abstract | Publisher Full Text
4. Young AF, Dobson AJ, Byles JE: Health services research using linked records: who consents and what is the gain?
Aust N Z J Public Health 2001, 25:417-420. PubMed Abstract
5. Tate AR, Calderwood L, Dezateux C, Joshi H, The Millennium Study Child Health Group:
records in a multi-ethnic national cohort study.
Int J Epidemiol 2006, 35:294-298. PubMed Abstract | Publisher Full Text
6. Harris T, Cook DG, Victor C, Beighton C, DeWilde S, Carey I: Linking questionnaires to primary care records: factors affecting consent in older
J Epidemiol Community Health 2005, 59:336-338. PubMed Abstract | Publisher Full Text
7. Klassen AF, Lee SK, Barer M, Raina P: Linking survey data with administrative information: characteristics associated with
intensive care unit follow-up study.
Can J Public Health 2005, 96:151-154. PubMed Abstract
8. Yawn BP, Yawn RA, Geier GR, Xia Z, Jacobsen SJ: The impact of requiring patient authorization for use of data in medical records research.
J Fam Pract 1998, 47:361-365. PubMed Abstract
9. Shih YT, Hung YT, Chang HY, Liu JP, Lin HS, Chang MC, Chang FC, Hsiung CA, Wu SL:
respondents of the 2001 National Health Interview Survey in Taiwan.
Tw J Public Health 2003, 22:465-473.
Pre-publication history
The pre-publication history for this paper can be accessed here:
http://www.biomedcentral.com/1472-6963/7/18/prepub
Patterns of consent in epidemiologic research: Evidence from over 25,000 responders.
Selection bias from requiring patients to give consent to examine data for health services research.
Health services research using linked records: who consents and what is the gain?
Joshi H, The Millennium Study Child Health Group: Mother's consent to linkage of survey data with her child's birth
Linking questionnaires to primary care records: factors affecting consent in older people.
Publisher Full Text
Linking survey data with administrative information: characteristics associated with consent from a neonatal
The impact of requiring patient authorization for use of data in medical records research.
Wu SL: The design, contents, operation and the characteristics of the
Sign up to receive new article alerts from BMC Health Services Research
Sign up

BMC Health Services Research - Full Text - Record Linkage Research and Informed Consent: Who Consents? PDF

Uploaded by

Copyright:

Available Formats

BMC Health Services Research - Full Text - Record Linkage Research and Informed Consent: Who Consents? PDF

Uploaded by

Document Information

Original Description:

Original Title

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

BMC Health Services Research - Full Text - Record Linkage Research and Informed Consent: Who Consents? PDF

Uploaded by

Copyright:

Available Formats

21/10/14 17:06 BMC Health Services Researcrmed consent: who consents?

You might also like