1 Addiction Research Institute Rotterdam (IVO), Rotterdam, 2 The Amsterdam Bureau for Research and Statistics (O+S), Amsterdam and 3 Tilburg University, Faculty of Social and Behavioural Sciences, Tilburg, The Netherlands
* Author to whom correspondence should be addressed at: Addiction Research Institute Rotterdam, Heemraadssingel 194, 3021 DM Rotterdam, The Netherlands. Tel.: +31 10 425 33 66; Fax: +31 10 276 39 88; E-mail: dotinga{at}ivo.nl
(Received 21 January 2004; first review notified 22 March 2004; in revised form and accepted 29 July 2004; Advance Access publication 29 March 2005)
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ABSTRACT |
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INTRODUCTION |
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Alcohol research among migrant groups with an Islamic religious background faces several methodological problems, which may generate unreliable alcohol data for these groups. First of all, probably owing to their Islamic religious background, Turks and Moroccans are often underrepresented in alcohol studies (Planije et al., 2000). When a sampled person does not respond to a survey request, non-response occurs, which may lead to biased results (Dillman et al., 2002
). Therefore, reducing non-response is a prerequisite for reliable data collection.
In general, non-response is higher in mail surveys compared with face-to-face and telephone interviews (Hox and de Leeuw, 1994). This effect may result from the fact that interviewers can persuade people to participate in the study. However, to some extent, this effect also seems to depend upon the subject of study. For instance, if the subject of study concerns a socially undesirable behavior, because of the higher perceived anonymity people may be more willing to participate in mail surveys than in face-to-face interviews (Schwartz et al., 1991
; Gmel, 2000
). This may apply in the Netherlands where Turks and Moroccans may view alcohol use as proscribed by their community.
In the case of face-to-face interviews, the ethnic background of the interviewer may also influence response rates (Weeks and Moore, 1981). Compared with an interviewer of a different ethnic background, an interviewer with the same ethnic background as the respondent may attain higher response rates, simply because the participants are more at ease with the interviewer. Interviewers with the same ethnic background would more easily elicit feelings of trust (Dotinga et al., 2004
), which may increase the willingness to participate in a study (Dillman et al., 2002
). However, empirical data on response rates in alcohol studies do not always support the idea that ethnic matching would enhance response rates. For example, ethnic matching of interviewer and respondent did not increase response rates in a survey on legal and illegal drug use among Moroccans in Amsterdam (Abraham et al., 1999
). In addition, two studies in the Netherlands showed that a relatively large number of Moroccans were willing to participate in a study in which a Dutch interviewer questioned them about alcohol use (Kemper, 1998
; Planije et al., 2000
). Thus, it remains unclear whether face-to-face interviews or mail surveys will elicit higher response rates in a study on alcohol use among Turks and Moroccans in the Netherlands. Moreover, the literature is not clear as to whether ethnically matched interviewers generate higher response rates. Therefore, the present study examines the effect of data collection mode and ethnicity of the interviewer on response rates in alcohol research.
In addition to the effect on response rates, the data collection mode and ethnicity of interviewers may also have an effect on alcohol reports. However, studies on the effect of data collection mode on self-reported alcohol use have yielded contradictory results. For example, Bongers (1998) showed that alcohol reports did not differ between mail surveys and personal interviews among inhabitants of Rotterdam. Aquilino (1994)
found that an admission of alcohol use was most likely in self-administered questionnaires and less likely in face-to-face interviews. However, a study among young Moroccans in the city of Utrecht (The Netherlands) showed that alcohol reports were higher in face-to-face interviews than in self-administered questionnaires (Planije et al., 2000
). Based on these studies, it remains unclear whether different data collection modes will produce differences in alcohol reports and if so, which data collection mode will yield more reliable alcohol data. In the present study, reports of higher alcohol consumption are considered to be the more reliable and accurate data. This assumption is generally made in alcohol research among the total population, because estimates of total alcohol consumption based on self-reports often cover only 4060% of the alcohol consumption based on other indices of alcohol use, such as sales data (Lemmens et al., 1988
; Rehm and Spuhler, 1993
). Because the religious and cultural background of Turks and Moroccans prescribes the abstinence of alcohol use, Turks and Moroccans can be expected to underreport their alcohol use to an even larger extent than the autochthonous population. Therefore, the assumption that higher alcohol reports constitute more accurate data is particularly tenable in research among Turks and Moroccans.
With respect to face-to-face interviews, the ethnicity of the interviewer may also influence alcohol reports. This is evident when respondents are questioned about culturally sensitive issues (Weeks and Moore, 1981) and when respondents believe that certain answers are not socially acceptable (Van 't Land, 2000
). Extensive research conducted in the USA has addressed ethnicity-of-interviewer effects and validity of self-reports (e.g. Campbell, 1981
; Weeks and Moore, 1981
; Anderson et al., 1988
; Davis, 1997
), indicating that these effects may be explained by the salience of the ethnicity of the interviewer throughout the interview and the tendency of the respondent to answer according to the racial attitudes of the interviewer. If these are indeed the operating mechanisms, Turks and Moroccans can be expected to be more willing to report alcohol use to a Dutch interviewer, since Dutch people generally approve of responsible alcohol use whereas Turkish and Moroccan people generally disapprove of any form of alcohol use. Furthermore, social control mechanisms in Turkish (Ögel, 1997
) and Moroccan societies (Van Gemert, 1998
) may explain higher alcohol reports to Dutch interviewers. These social control mechanisms tend to discourage disrespectful behavior with respect to family and community norms, e.g. to abstain from alcohol. Therefore, Turks and Moroccans may be more willing to respond to alcohol questions asked by a Dutch interviewer than by an ethnically matched interviewer.
The present study investigates the above mentioned methodological issues using an experimental design. More specifically, the following research questions will be addressed with respect to alcohol research among Turks and Moroccans in the Netherlands: (i) which method will yield higher response rates, mail questionnaires or face-to-face interviews? (ii) which interviewer will attain higher response rates, a Dutch or a Turkish/Moroccan interviewer? (iii) which method will yield higher alcohol reports, mail surveys or face-to-face interviews? (iv) which interviewer will attain higher alcohol reports, a Dutch or a Turkish/Moroccan interviewer?
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MATERIALS AND METHODS |
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From the municipal register of Rotterdam, 744 second-generation Turks and 753 second-generation Moroccans (16 years) were randomly selected from four neighborhoods (selected for their geographic distribution) in Rotterdam. To gain insight into the impact of the data collection mode on response rates and alcohol reports, a random sample of 269 Turks and 271 Moroccans was selected to be interviewed face-to-face. Half of the Turks and Moroccans allocated to the face-to-face condition were ethnically matched to the interviewer and the other half was matched to a Dutch interviewer. The remainder of both the samples (475 Turks and 482 Moroccans) received a mailed questionnaire. All sample selections were stratified for gender and neighborhood.
From the original sample of 744 Turks, 14 respondents were excluded from analyses because they belonged to the first-generation Turks, one Turk had completed the same questionnaire twice, and another one had completed the questionnaire on paper at the door, whilst he should have answered the questions face-to-face. The final sample consisted of 728 Turks (463 in the written data collection mode, and 265 in the interview mode): of these, 385 were men and 343 were women, with an age range of 1634 years (M = 22). From the total sample of 753 Moroccans, eight respondents were excluded from analyses because they were born in Morocco (first-generation Moroccans). The final sample consisted of 745 Moroccans (481 in the written data collection mode, and 264 in the interview mode): of these, 360 were men and 385 were women, with an age range of 1634 years (M = 20.8).
Procedures
Interviewers were recruited among Turkish and Moroccan university students belonging to the second generation (Dotinga et al., 2004). Ten Dutch interviewers (of which four were male, mean age of 24.5 years, and six were female, mean age of 23.6 years), eight Turkish interviewers (of which three were male, mean age of 23.3 years, and five were female, mean age of 23.6 years) and six Moroccan interviewers (of which three were male, mean age of 20.3 years and three were female, mean age of 20.3 years) participated in the study. Interviewers and respondents were gender matched. Only female students who did not wear a headscarf were selected as interviewers. Wearing a headscarf is a symbol of the Islamic religion and since abstention from alcohol use is an Islamic prescription rule, this might have influenced the answers about alcohol use of respondents. Since both the interviewers and the interviewees comprised second-generation Turks and Moroccans (i.e. Turks and Moroccans born in the Netherlands) interviews were performed in Dutch. To prevent interviewers from interviewing people with whom they were acquainted, interviewers were not allowed to work in the neighborhood where they lived themselves. Interviewers attended an extensive training session, in which information was given on the background of the study, the protocol that had to be followed and techniques that had to be used. For example, interviewers were instructed to interview respondents without the presence of others, e.g. in a separate room or somewhere else. If this was not possible they had to make another appointment at a time in which the respondent could be interviewed alone. Furthermore, the questionnaire was discussed and the interview was practised by means of role playing.
Turks and Moroccans selected for face-to-face interviews received a letter which explained the study and also announced that an interviewer would visit them in the coming weeks. Interviewers were instructed to approach an interviewee at home at least three times at different time points. Turks and Moroccans who were allocated to the written data collection mode received a mailed questionnaire at the same time that the interviewers started the interviews. To increase the response rate and to keep the procedures for both data collection modes as similar as possible, non-respondents to the mail survey received two reminders after 3 and 6 weeks, respectively. Both reminders included another copy of the same questionnaire. Four months after the start of the data collection process, non-respondents to the mail survey and the face-to-face interviews received a shortened mailed questionnaire.
Measurements
Alcohol use was measured according to the quantity frequencyvariability method (QFVmethod) using six questions: (i) Which alcoholic drinks did you use during the past six months (beer, wine, strong alcoholic beverages, I haven't drunk alcohol during the past 6 months, I have never drunk alcohol); (ii) How many weekend days (Friday through Sunday) do you drink on average (3 days, 2 days, 1 day, occasionally, I never drink on weekend days) (F); (iii) How many glasses do you drink on average on a weekend day (>11 glasses, 710 glasses, 6 glasses, 45 glasses, 3 glasses, 2 glasses, 1 glass) (Q); (iv) How many weekdays (Monday through Thursday) do you drink on average (4 days, 3 days, 2 days, 1 day, occasionally, I never drink on weekdays) (F); (v) How many glasses do you drink on average on a weekday (Q); (vi) Have you ever drunk six or more glasses in 1 day during the past 6 months? (every day, 5 or 6 times a week, 3 or 4 times a week, 1 or 2 times a week, 13 times a month, 35 times per six months, 1 or 2 times per 6 months, never) (V).
Respondents were classified as abstainers if they reported not having had a drink in the previous 6 months. Weekly alcohol use based on the QF items was assessed by the sum of alcohol use on weekdays (number of drinking weekdays x number of glasses on a weekday) and weekend days (number of drinking weekend days x number of glasses on a weekend day), (testretest reliability of this QF scale was r = 0.77; P < 0.01). If respondents reported (both on weekdays and weekend days) only occasional drinking they were classified as occasional drinkers, otherwise they were classified as regular drinkers. Weekly alcohol use based on the variability item was assessed by multiplying the number of days per week that a person drank at least six glasses of alcohol x six glasses. When an answering category included a range, the mean of that range was taken and multiplied by six (e.g. 13 times a month: mean is 2 times a month = 0.5 times a week, multiplied by six = 3). When weekly alcohol use according to the QF items was inconsistent with weekly alcohol use according to the V item, the highest score was taken as the indicator for weekly alcohol use. Respondents were defined as excessive drinkers according to two definitions: (i) based on the variability item: if they reported drinking at least once a week six or more glasses of alcohol (Garretsen, 1983), or (ii) based on the QF items: if women reported drinking >13 glasses of alcohol a week and men reported drinking >20 glasses of alcohol a week (e.g. San José, 2000
; Toet et al., 2003
).
Socio-demographic factors measured in this study were gender, age, marital status (having a partner or not) and education. Education was defined as the respondent's highest attained education level: (i) primary school, (ii) lower vocational/general, (iii) intermediate vocational/general and (iv) higher general/higher vocational/university.
Analyses
First, the distribution of background factors was compared between the respondents to the different data collection modes. Statistical significance for these analyses was estimated by Chi-square test. Second, the effect of data collection mode (total sample) and ethnic background of the interviewer (interviewed sample) on response rates was tested. To determine statistical differences, logistic regression models were fitted, including age and gender. Third, the effects of data collection mode (total sample) and ethnic background of the interviewer (interviewed sample) were tested on alcohol reports. Logistic regression models were fitted (including age, gender, marital status and educational level) to test the effect of data collection mode and ethnicity of interviewer on the number of drinkers and on excessive drinking. For the latter, a distinction was made between regular and occasional drinkers, since occasional drinkers could distort the results with respect to the quantity of alcohol use. Variance analyses (including age, gender, marital status and educational level) were conducted to test the effect of data collection mode and ethnicity of interviewer on mean alcohol use in both the total sample of drinkers and among the regular drinking sample.
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RESULTS |
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Self-reported alcohol use
With respect to the effect of data collection mode on the number of drinkers (Table 3), no significant differences were found between respondents of the mail survey and respondents of the interview. With respect to the effect of ethnicity of interviewers on the number of drinkers, data showed that respondents who were interviewed by a Dutch interviewer had significant higher odds of reporting alcohol use in the previous 6 months, compared with respondents who were interviewed by a Turkish/Moroccan interviewer [OR = 3.05, 95%CI (1.516.18)]. Correcting for the presence of others by including this factor as a covariate in the regression model did not change these results.
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DISCUSSION |
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Third, we want to comment on the response rates in our study. Although response rates are higher in face-to-face interviews compared with mail surveys, response rates are low in both data collection modes. However, it is comparable with other Dutch alcohol studies (e.g. Bongers and van Oers, 1998; Planije et al., 2000
; Lahaut et al., 2002
) and is partly explained by the fact that participation in governmental surveys is not obligatory (De Heer, 1999
). Furthermore, people may be tired of participating in surveys, because they are approached very often. Fourth, conducting interviews in participants' homes may have had some adverse impact on attaining 'private' accounts (Malseed, 1990
) of alcohol consumption. However, this was necessary to keep the experimental conditions of both data collection modes the same. We tried to rule out the effect by instructing the interviewers that they had to interview people alone, without the presence of others.
Finally, we want to comment on the way in which the data were analyzed. It has been argued that Turks and Moroccans, although both Islamic oriented, are different in their cultural and religious background. Therefore, studying these two ethnic groups simultaneously would generate oversimplified insights. However, since power problems were evident when analyzing Turks and Moroccans separately, it was decided to combine both samples in the analysis. Moreover, analysis performed separately among Turks and Moroccans, revealed effects in the same directions for both ethnic groups, supporting our analysis among the combined sample.
Based on the results of the present study, we have to draw different conclusions about the most appropriate way to measure alcohol use among second generation Turks and Moroccans in the Netherlands, depending on the goal of the study. To measure the prevalence of alcohol use in the previous 6 months, face-to-face interviews with Dutch interviewers seem most appropriate, but to measure mean alcohol consumption levels and excessive drinking, mail surveys seem more appropriate.
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ACKNOWLEDGEMENTS |
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REFERENCES |
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Abraham, M. D., Cohen, P. D. A., Van Til, R. J. et al. (2000) Licit and illicit drug use in Amsterdam lll. Developments in drug use 19871997. CEDRO, Amsterdam.
Aquilino, W. S. (1994) Interview mode effects in surveys of drug and alcohol use, a field experiment. Public Opinion Quarterly 58, 210240.[Abstract]
Anderson, B. A., Silver, B. D. and Abrahamson, P. R. (1988) The effects of race of the interviewer on measures of electoral participation by blacks in SRC National Election Studies. Public Opinion Quarterly 52, 289324.[Abstract]
Bik, M. and Stolk, C. (2002) De bevolkingsprognose van Rotterdam 2017. COS, Rotterdam.
Bongers, I. M. B. (1998) Problem drinking among the general population: a public health issue? PhD thesis. Erasmus University Rotterdam.
Bongers, I. M. B. and van Oers, J. A. M. (1998) Mode effects on self-reported alcohol use and problem drinking: mail questionnaires and personal interviewing compared. Journal of studies on Alcohol 59, 280285.[ISI][Medline]
Campbell, B. A. (1981) Race-of-interviewer effects among southern adolescents. Public Opinion Quarterly 45, 234244.
CBS (Central Bureau of Statistics) (2002) Allochtonen in Nederland. CBS, Voorburg/ Heerlen.
Davis, D. W. (1997) Non-random measurement error and race of interviewer effects among African Americans. Public Opinion Quarterly 61, 183207.
De Heer, W. (1999) International response trends: results of an international survey. Journal of Official Statistics 15, 129142.
Dillman, D. A. and Carley-Baxter, L. R. (2000) Structural determinants of mail survey response rates over a 12-year period, 19881999. Proceedings of the section on survey method. The American Statistical Association, Alexandria, VA. Available at: http://survey.sesrc.wsu.edu/dillman.
Dillman, D. A., Eltinge, J. L., Groves, R. M. et al. (2002) Survey Nonresponse in Design, Data Collection, and Analysis. In Survey Nonresponse, Groves, R. M., Dillman, D. A., Eltinge, J. L. and Little, R. J. A. eds, pp. 326. John Wiley & Sons, New York.
Dotinga, A., van den Eijnden, R. J. J. M., Bosveld, W. et al. (2004) Methodological problems related to alcohol research among Turks and Moroccans living in the Netherlands: findings from Semi-structured Interviews. Ethnicity & Health 9, 139151.[ISI][Medline]
Garretsen, H. F. L. (1983) Probleemdrinken: prevalentiebepaling, beïnvloedende factoren en preventiemogelijkheden. Dissertation. Swets & Zeitlinger B. V., Lisse.
Gmel, G. (2000) The effect of mode of data collection and of non-response on reported alcohol consumption: a split sample study in Switzerland. Addiction 95, 123134.[CrossRef][ISI][Medline]
Gorissen, W. H. M., Ticheler, P. C. M., van Kessel, R. P. M. et al. (1988) Gezondheidspeiling Utrecht. Resultaten van de Gezondheidspeiling Utrecht 19861987. Municipal Health Authority, Utrecht.
Hox, J. J. and De Leeuw, E. D. (1994) A comparison of nonresponse in mail, telephone, and face-to-face surveys. Quality & Quantity 28, 329344.[CrossRef][ISI]
Kemper, F. (1998) Gezocht: Marokkanen. Methodologische problemen bij het werven en interviewen van allochtone respondenten. Migrantenstudies 1, 4357.
Lahaut, V. M. H. C. J., Jansen, H. A. M., van de Mheen, D. et al. (2002) Non-response bias in a sample survey on alcohol consumption. Alcohol & Alcoholism 37, 256260.
Lemmens, P., Knibbe, R. A. and Tan, F. (1988) Weekly recall and diary estimates of alcohol consumption in a general population survey. Journal of Studies on Alcohol 49, 131135.[ISI][Medline]
Malseed, J. (1990) Alcohol in Asian and Afro-Caribbean Communities. School of Independent Studies, Lancaster University.
Ögel, K (1997) Het gebruik van middelen onder de in Nederland wonende Turkse bevolkingsgroep. Psychiatrisch Ziekenhuis Bakirkoy. Afdeling onderzoek en behandeling Alcohol, Istanbul.
Planije M., Verdurmen J. and van Wamel, A. (2000) Alcohol- en druggebruik onder jonge Marokkanen in de gemeente Utrecht. Netherlands Institute of Mental Health and Addiction (Trimbos Instituut), Utrecht.
Rehm, J. and Spuhler, T. (1993) Measurement error in alcohol consumption: the Swiss Health Survey. European Journal of Clinical Nutrition 47, S25S30.[Medline]
San José, B. (2000) Alcohol consumption and health: Contributions to the explanation of the U-shaped curve. PhD thesis. Erasmus University Rotterdam.
Schwartz, N., Strack, F., Hippler, H.-J. et al. (1991) The impact of administration mode on response effects in survey measurement. Applied Cognitive Psychology 5, 193212.[ISI]
Toet, J., Verdurmen, J. E. E., van Dijk, A. P. et al. (2003) Prevalentie van alcoholgebruik, roken en cannabisgebruik; Utrecht vergeleken met Parkstad Limburg en Rotterdam. Tijdschrift voor Gezondheidswetenschappen 81, 346354.
Van Eijsden, M., de Geus, G. and van Ameijden, E. J. C. (2004) De gezondheid van de Utrechtse jeugd: trend en sociaaldemografische verschillen. Tijdschrift voor Gezondheidswetenschappen 82, 1220.
Van Gemert, F. (1998) Ieder voor zich. Kansen, cultuur en criminaliteit van Marokkaanse jongens. Het Spinhuis, Amsterdam.
Van 't Land, H. (2000) Similar Questions; Different Meanings. PhD thesis. Free University, Amsterdam.
Weeks, M. F. and Moore, R. P. (1981) Ethnicity-of-interviewer effects on ethnic respondents. Public Opinion Quarterly 45, 245249.[Abstract]
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