Comparing probability and non-probability sampling methods in Ecstasy research: implications for the internet as a research tool

Parents' acceptance attitudes towards the vaccination of children based on M-LSGDM approach in China: a cross-sectional study

OBJECTIVES

Ensuring that children receive timely vaccinations is paramount for preventing infectious diseases, and parental attitude plays a pivotal role in this process. This study addresses this gap in the existing literature by examining parental attitudes towards vaccinating their children.

DESIGN

A cross-sectional study.

METHODS

An online survey including parents' sociodemographic characteristics, risk perception and attitudes towards child vaccination towards COVID-19 was conducted. The modified large-scale group decision-making approach for practicality and binary logistic regression was used to identify the predictors influencing parents' decision-making.

RESULTS

Of the 1292 parents participated, 957 (74.1%) were willing to vaccinate their children, while 335 (25.9%) refused the vaccination. The study indicated that age, parental anxiety regarding child vaccination, concerns about the child's susceptibility to the disease, opinions towards vaccination benefits versus disadvantages, place of residence, average family income and children's health were significant predictors (p<0.05).

CONCLUSIONS

While most parents supported childhood vaccination, some opposed it. Addressing persistent barriers is crucial to ensure widespread vaccination and child well-being.

Hope, death anxiety and simplified coping style scores of nursing students during the outbreak of COVID-19: A cross-sectional study

ABSTRACT

Nursing students are the main force of future nursing development, and their hope and death anxiety are important aspects of their coping styles and clinical practice.The present study examined the relationships between hope, death anxiety and simplified coping style scores of nursing students during the outbreak of COVID-19.Between February and April 2020, a cross-sectional descriptive study was performed using a Sojump online survey, and 870 nursing students completed the herth hope (HH), death anxiety scale (DAS) and simplified coping style questionnaire. The data were analyzed using t-tests, one-way analysis of variance (ANOVA), and multiple linear regression in SPSS 23.0 (IBM Corp, Armonk, NY).The average HH, DAS and active and passive coping scores of the 870 nursing students were 3.07 ± 0.32, 3.01 ± 0.37, 2.84 ± 0.48, and 2.25 ± 0.50, respectively. Participants with contact experience with individuals with suspected or confirmed COVID-19 were more likely to adopt passive coping styles than students without contact experience (t = 5.019, P = .025). Being older and having higher inner positive readiness and expectancy, a lower inner sense of temporality and future, and lower time awareness were predictors of passive coping styles (P < .05). Living in cities (vs towns) and having a higher inner positive readiness and expectancy, a higher inner sense of temporality and future and lower cognition of death were predictors of active coping styles (P < .05).The findings of this study suggest that hope and death anxiety are important aspects of the coping styles of nursing students. Nursing educators should emphasize the role of hope, further deepen the death education mode, and perform scientific and reasonable death education programmes to reduce the death anxiety level of nursing students to promote their coping styles in crisis.

Measures of the Degree of Departure from Ignorable Sample Selection

With the current focus of survey researchers on "big data" that are not selected by probability sampling, measures of the degree of potential sampling bias arising from this nonrandom selection are sorely needed. Existing indices of this degree of departure from probability sampling, like the R-indicator, are based on functions of the propensity of inclusion in the sample, estimated by modeling the inclusion probability as a function of auxiliary variables. These methods are agnostic about the relationship between the inclusion probability and survey outcomes, which is a crucial feature of the problem. We propose a simple index of degree of departure from ignorable sample selection that corrects this deficiency, which we call the standardized measure of unadjusted bias (SMUB). The index is based on normal pattern-mixture models for nonresponse applied to this sample selection problem and is grounded in the model-based framework of nonignorable selection first proposed in the context of nonresponse by Don Rubin in 1976. The index depends on an inestimable parameter that measures the deviation from selection at random, which ranges between the values zero and one. We propose the use of a central value of this parameter, 0.5, for computing a point index, and computing the values of SMUB at zero and one to provide a range of the index in a sensitivity analysis. We also provide a fully Bayesian approach for computing credible intervals for the SMUB, reflecting uncertainty in the values of all of the input parameters. The proposed methods have been implemented in R and are illustrated using real data from the National Survey of Family Growth.

Using Facebook to recruit to a national online survey investigating complementary medicine product use in pregnancy and lactation: A case study of method

BACKGROUND

Online recruitment can be targeted efficiently to recruit specific samples for survey research. It has been shown to be a cost-effective method of recruitment, and useful for geographically dispersed populations.

OBJECTIVES

To describe the use of Facebook to recruit a targeted sample of expectant and breastfeeding mothers to a national online survey. Different techniques to assess response rates using data provided by Facebook are also described.

METHODS

Participants accessed an anonymous online survey through a link included in posts from a Facebook page specifically set up for the research. Recruitment strategies were primarily of two types. Firstly, Facebook was paid to promote posts by displaying them on potential participants' Facebook feeds. Secondly, by purposive and snowball recruitment through the sharing of posts on relevant Facebook pages. Post success was measured by the reach, impressions, link clicks, post clicks, and click through rates; and for boosted posts, the cost per day, and cost per engagement with the post as well. Traditional methods of calculating response rates, and response rates using post clicks and survey link clicks were calculated.

RESULTS

After 10 weeks of recruitment, 1418 participants had enrolled in the study, and of these 810 (57.1%) completed the 20-minute (70 question) survey. Women participated from across Australia. Both paid and purposive approaches to promotion contributed to recruitment success. Paid promotions at higher costs for fewer days were the most successful. Total paid promotion costs were (Australian) $1147.97 (or $1.44 per completed survey). Purposive promotion was slower, but also contributed significantly to the number of people who saw the posts and clicked through to the survey. Traditional response rate calculations showed a response rate of 0.8%. Using post clicks and survey link clicks in calculations, resulted in response rates of 23.1% and 42.7%, respectively.

CONCLUSIONS

A combination of paid promotions and purposive and snowball recruitment on Facebook were used to successfully recruit 1418 participants resulting in 810 completed surveys over a 10-week period, at a low cost per participant. Use of additional methods to measure response rates may be useful in measuring the success of using Facebook posts in recruitment.

"How do online and offline sampling compare in a multinational study of drug use and nightlife behaviour?"

BACKGROUND

Online sampling is widely used to recruit hard to reach samples such as drug users at nightlife events. We conducted the first study comparing differences in demographics, drug use and nightlife behaviour between an online sample of young adults engaging with the European nightlife scene, and an offline sample recruited at nightclubs and festivals in Europe.

METHODS

Online participants who attended at least six nightlife events in the past 12 months were recruited using social media advertising (May-November 2017). Offline participants were recruited at nightclubs and festivals using a random intercept method (May-November 2017). Samples were compared with respect to age, gender, past year use of alcohol, cannabis, cocaine, ecstasy/MDMA and amphetamines, and past year attendance at nightclubs, licensed festivals, illegal festivals, pubs and house-parties.

RESULTS

6153 online and 3529 offline participants were recruited. When adjusting for differences in age and gender, online participants were less likely to have used each drug and to have attended illegal festivals, pubs and house-parties in the past 12 months. The online sample also used each drug and attended each venue, with the exception of nightclubs, less frequently on average than offline participants. Adjusted odds ratios (range 0.37 to 1.39) and regression coefficients (range -0.84 to 0.07) indicate that the majority of observed differences between the samples were of a small effect size.

CONCLUSIONS

Estimates of drug use and nightlife engagement are more conservative when using online sampling compared to venue based sampling. Observed differences were generally small in effect, indicating good overall representativeness when using online sampling in the European nightlife scene.

Indices of non-ignorable selection bias for proportions estimated from non-probability samples

Rising costs of survey data collection and declining response rates have caused researchers to turn to non-probability samples to make descriptive statements about populations. However, unlike probability samples, non-probability samples may produce severely biased descriptive estimates due to selection bias. The paper develops and evaluates a simple model-based index of the potential selection bias in estimates of population proportions due to non-ignorable selection mechanisms. The index depends on an inestimable parameter ranging from 0 to 1 that captures the amount of deviation from selection at random and is thus well suited to a sensitivity analysis. We describe modified maximum likelihood and Bayesian estimation approaches and provide new and easy-to-use R functions for their implementation. We use simulation studies to evaluate the ability of the proposed index to reflect selection bias in non-probability samples and show how the index outperforms a previously proposed index that relies on an underlying normality assumption. We demonstrate the use of the index in practice with real data from the National Survey of Family Growth.

Recruitment Strategies of Indian Men Who Have Sex with Men in the State of Maharashtra Into an Online Survey

In this manuscript, we report lessons learned from our efforts to recruit Indian men and transgender women/hijras who have sex with men into an online cross sectional study. Between September 2013 and May 2014, we implemented a seven-phased recruitment strategy that included the use of online and offline strategies to enroll a total of 449 participants into an online survey about recent sexual behavior and various psychosocial measures. The phases were implemented sequentially and cost-per-eligible participant was calculated. Using social media and collaborating with organizers of community events proved the most effective strategies for recruiting Indian MSM into online research.

Migrants Examined for Determinants of psychopathology through INternet Assessment (MEDINA) study: a cross-sectional study among visitors of an Internet community

INTRODUCTION

Migration is a risk factor for the onset of psychopathology. A range of social factors may play a role in the aetiology of psychiatric disorders in migrants. A better understanding of these associations is needed to develop preventive interventions to reduce the disease burden in the migrant population. Research among minority groups is generally time consuming and it is difficult to recruit participants. Internet can offer interesting new possibilities to conduct research among ethnic minorities. This article describes the design of an epidemiological study in the Moroccan-Dutch population, which will be entirely performed online. We investigate the association between social factors and psychopathology.

METHODS AND ANALYSIS

The website Marokko.nl is visited by 70% of the young Moroccan-Dutch population in the Netherlands. This website therefore provides a unique possibility for research within this population. We will conduct a survey with online questionnaires via this website. The online survey consists of several validated short self-report questionnaires, measuring depressive and anxiety symptoms (The Kessler Psychological Distress Scale (K10)), psychotic symptoms (The Prodromal Questionnaire-16 (PQ-16)) and instruments measuring discrimination, social support and social defeat. Furthermore, demographic characteristics are collected. We will use univariate and multivariate methods for analysing the data.

ETHICS AND DISSEMINATION

The local medical ethical committee has assessed the study protocol and judged that the study could be conducted without their approval. Knowledge dissemination will take place through peer-reviewed publication in scientific journals as well as publication for participants on the project website.

DISCUSSION

In this study we further explore the association between psychopathology and social factors within an online Moroccan-Dutch sample. The recruitment of participants via the website Marokko.nl creates a big advantage in collecting a large sample of a specific migrant population. Strengths and limitations of the methodology are discussed. Furthermore, we review the advantages and challenges of online epidemiological research methods.

Psychological Distress and Drug Use Patterns of Young Adult Ecstasy Users: A Complementary Analysis of Australian Datasets

We examine psychological distress (PD) in young adult Ecstasy users in relation to age of initiation and frequency of use of Ecstasy, cannabis, alcohol, and tobacco. Using two Australian community samples, we assess whether different sampling methods produce comparable estimates of these associations. The Natural History Study of Drug Use (NHSDU; N = 339) in 2009 used population sampling and the 2009 Ecstasy and Related Drug Reporting System (EDRS; N = 359) used purposive sampling. Participants, aged 19-23 years, were recurrent Ecstasy users. PD was assessed using Kessler 10 in the EDRS and Hospital Anxiety Depression Scale in the NHSDU. In both samples, PD was associated with daily tobacco use and early drug initiation, but not frequent Ecstasy use. One-third smoke tobacco daily. Study limitations and implications are noted.

Recruitment Strategies of Methamphetamine-Using Men Who Have Sex with Men into an Online Survey

Recruiting hidden populations into online research remains challenging. In this manuscript, we report lessons learned from our efforts to recruit methamphetamine-using men who have sex with men. Between July and October 2012, we implemented a four-phase recruitment strategy to enroll a total of 343 methamphetamine-using MSM into an online survey about recent substance use, sexual behavior, and various psychosocial measures. The four phases were implemented sequentially. During phase one, we placed advertisements on mobile applications, and during phase two, we placed advertisements on traditional websites formatted for browsers. During phase three, we used e-mail to initiate snowball recruitment, and during phase four, we used social media for snowball recruitment. Advertisements on mobile devices and websites formatted for browsers proved to be expensive options and resulted in few eligible participants. Our attempts to initiate a snowball through e-mail also proved unsuccessful. The majority (n=320) of observations in our final dataset came from our use of social media. However, participant fraud was a concern, requiring us to implement a strong participant verification protocol. For maximum recruitment and cost-effectiveness, researchers should use social media for recruitment provided they employ strong participant verification protocols.

Selection bias of Internet panel surveys: a comparison with a paper-based survey and national governmental statistics in Japan

PURPOSE

To investigate the selection bias of an Internet panel survey organized by a commercial company.

METHODS

A descriptive study was conducted. The authors compared the characteristics of the Internet panel survey with a national paper-based survey and with national governmental statistics in Japan.

RESULTS

The participants in the Internet panel survey were composed of more women, were older, and resided in large cities. Regardless of age and sex, the prevalence of highly educated people in the Internet panel survey was higher than in the paper-based survey and the national statistics. In men, the prevalence of heavy drinkers among the 30- to 49-year-old population and of habitual smokers among the 20- to 49-year-old population in the Internet panel survey was lower than what was found in the national statistics.

CONCLUSIONS

The estimated characteristics of commercial Internet panel surveys were quite different from the national statistical data. In a commercial Internet panel survey, selection bias should not be underestimated.

Transition to and from injecting drug use among regular ecstasy users

There is a scant amount of research investigating injecting drug use among people not selected on the basis of their injecting behaviour, and less attention has been given to stimulant users who may have a different experience with injecting drug use than opioid users who are more commonly studied. The current study aimed to investigate initiation to, and transition from, injecting drug use among a sentinel sample of regular ecstasy users in Australia. Participants were regular ecstasy users recruited across Australia in 2007 who were administered a structured interview that contained questions regarding initiation to injecting, reasons for injecting cessation, and likelihood of future injecting. Among those with a history of injecting drug use, injecting first occurred at a similar age to that of first ecstasy use. The majority did not inject themselves at the first occasion, and two-fifths were under the influence of other drugs at the time. Two-fifths of injectors had not injected in the past 6 months, with many relating this to concerns surrounding stigma. Route of drug administration is clearly not static, and the findings from this study suggest that some who have ceased injecting may still be at risk for future injecting.

Using the internet to research hidden populations of illicit drug users: a review

AIMS

To review the current research of hidden populations of illicit drugs users using web-based methods and discuss major advantages and disadvantages.

METHODS

Systematic review of 16 databases, including PubMed, PsycINFO (EBSCOhost), CSA Sociological Abstracts, Expanded Academic ASAP and Google Scholar.

FINDINGS

Substances researched were most commonly 'party/club drugs' (such as ecstasy) and cannabis. All of the studies reviewed concluded that the internet is a useful tool for reaching hidden populations, but is likely to impose some bias in samples. Advantages include: access to previously under-researched target groups; speed; international applications; increased ease of data entry; and improved confidentiality for respondents. The major disadvantage is a lack of representativeness of samples.

CONCLUSIONS

Internet research is successful at accessing hidden populations of illicit drugs users, when appropriately targeted and provides unprecedented opportunities for research across a wide range of topics within the addictions field. Findings are unlikely to be generalisable to the general public, but appropriate for describing target populations.