Hidden Populations, Online Purposive Sampling, and External Validity

Barratt, Monica J.; Ferris, Jason; Lenton, Simon

doi:10.1177/1525822x14526838

Cited by 140 publications

(96 citation statements)

References 36 publications

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“…Therefore, as participants in our survey may have a greater interest in or experience with drugs, they may not be representative of the wider population. However, as our interest is in identifying emerging substances and new trends in drug use, rather than highlighting current trends in the general population, the benefits of the sampling strategy and web‐based design in accessing otherwise hidden populations actually improves our capacity to answer these kinds of questions among people who use illicit drugs . Given the above, it is important not to interpret the findings reported here as prevalence estimates.…”

Section: Discussionmentioning

confidence: 97%

Correlates of new psychoactive substance use among a self-selected sample of nightclub attendees in the United States

et al. 2016

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Background and Objectives Although new psychoactive substances (NPS) continue to emerge at a rapid rate, US national surveys only measure the use of non-specific categories of NPS and are not designed to access high-risk populations. In this paper we report lifetime use of specific NPS (of 58) and examine correlates of use among a high-risk population: nightlife attendees. Methods The self-selected sample from the Global Drug Survey (2013) consisted of 2,282 respondents in the US, aged 16–60 years, who reported nightclub attendance in the last year. Multivariable logistic regression models determined unique predictors of lifetime use. Results Lifetime use of a wide range of NPS was reported (any NPS; 46.4%), including synthetic cannabinoids (24.8%), tryptamines (eg, 4-AcO-DMT, 23.0%), psychedelic phenethylamines (eg, 2C-B, 25I-NBOMe; 21.7%), euphoric stimulants (eg, BenzoFury; 16.2%), and synthetic cathinones (eg, methylone; 10.5%). Females (AOR = 0.49 [.41, .60]) and older respondents (age 22–60; AOR = .73 [.59, .89]) were at lower odds of reporting any lifetime NPS use. Frequent nightclub attendance was associated with increased odds of reporting lifetime NPS use overall (eg, weekly compared with less than once a month, AOR =2.33 [1.70,3.19]), but not specifically with synthetic cannabinoid use. Discussion and Conclusions Among a self-selected sample of nightclub attendees, a large range of novel substances were reported, and young attendees, males, and those who attended more frequently were at increased odds of reporting use. Scientific Significance Harm reduction initiatives are needed to reduce risk of harm in this population, where environmental characteristics may augment risks associated with consuming lesser-known psychoactive substances.

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Section: Discussionmentioning

confidence: 97%

Correlates of new psychoactive substance use among a self-selected sample of nightclub attendees in the United States

et al. 2016

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“…A convenience sample of parents was recruited via trial information leaflets and invitations, and with the support of the research nurses. 76,77 All participants had reached the end of the trial prior to participating and they represented all recruiting centres. In total, 28 mothers and five fathers participated, representing 11% of all trial participants.…”

Section: Data Collectionmentioning

confidence: 99%

“…Children were recruited using a convenience sampling strategy 76,77 via the study research nurses. They represented all of the recruiting centres and had all completed the trial before participating.…”

Section: Data Collectionmentioning

confidence: 99%

Randomised controlled trial of silk therapeutic garments for the management of atopic eczema in children: the CLOTHES trial

Kim

Bradshaw

Sach

et al. 2017

Health Technol Assess

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Background: Atopic eczema (AE) is a chronic, itchy, inflammatory skin condition that affects the quality of life of children and their families. The role of specialist clothing in the management of AE is poorly understood.Objectives: To assess the effectiveness and cost-effectiveness of silk garments for the management of AE in children with moderate to severe disease.Design: Parallel-group, observer-blind, randomised controlled trial of 6 months’ duration, followed by a 2-month observational period. A nested qualitative study evaluated the beliefs of trial participants, health-care professionals and health-care commissioners about the use of silk garments for AE.Setting: Secondary care and the community in five UK centres.Participants: Children aged 1–15 years with moderate or severe AE.Interventions: Participants were randomised (1 : 1 using online randomisation) to standard care or standard care plus 100% silk garments made from antimicrobially protected knitted sericin-free silk [DermaSilkTM (AlPreTec Srl, San Donà di Piave, Italy) or DreamSkinTM (DreamSkin Health Ltd, Hatfield, UK)]. Three sets of garments were supplied per participant, to be worn for up to 6 months (day and night). At 6 months the standard care group received the garments to use for the remaining 2-month observational period.Main outcome measures: Primary outcome – AE severity using the Eczema Area and Severity Index (EASI) assessed at 2, 4 and 6 months, by nurses blinded to treatment allocation. EASI scores were log-transformed for analysis. Secondary outcomes – patient-reported eczema symptoms (Patient Oriented Eczema Measure); global assessment of severity (Investigator Global Assessment); quality of life of the child (Atopic Dermatitis Quality of Life, Child Health Utility – 9 Dimensions), family (Dermatitis Family Impact Questionnaire) and main carer (EuroQoL-5 Dimensions-3 Levels); use of standard eczema treatments (e.g. emollients, topical corticosteroids); and cost-effectiveness. The acceptability and durability of the clothing, and adherence to wearing the garments, were assessed by parental/carer self-report. Safety outcomes – number of skin infections and hospitalisations for AE.Results: A total of 300 children were randomised (26 November 2013 to 5 May 2015): 42% female, 79% white, mean age 5 years. The primary analysis included 282 out of 300 (94%) children (n = 141 in each group). Garments were worn for at least 50% of the time by 82% of participants. Geometric mean EASI scores at baseline, 2, 4 and 6 months were 8.4, 6.6, 6.0, 5.4 for standard care and 9.2, 6.4, 5.8, 5.4 for silk clothing, respectively. There was no evidence of difference between the groups in EASI score averaged over all follow-up visits adjusted for baseline EASI score, age and centre (ratio of geometric means 0.95, 95% confidence interval 0.85 to 1.07; p = 0.43). This confidence interval is equivalent to a difference of –1.5 to 0.5 in the original EASI scale units. Skin infections occurred in 39 out of 141 (28%) and 36 out of 142 (25%) participants for sta...

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“…Like other studies of hidden populations, this study recruited a purposive sample, rather than a probability sample . Given the sampling methods used, findings cannot be seen to estimate the prevalence of double dropping in the wider population of people who use ecstasy at festivals.…”

Section: Discussionmentioning

confidence: 99%

Double dropping down under: Correlates of simultaneous consumption of two ecstasy pills in a sample of Australian outdoor music festival attendees

Grigg

Barratt

Lenton

2018

Drug and Alcohol Review

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Introduction and Aims. The term 'double dropping' refers to a person consuming two drugs simultaneously, typically two ecstasy pills. This practice has been reported in numerous countries, including Australia; however, the prevalence and correlates of double dropping among ecstasy users is unknown. Double dropping is particularly risky when adulteration of 'ecstasy' with novel substances and higher dosages of MDMA in pure ecstasy pills have both been increasingly reported. This paper investigates the prevalence and correlates of double dropping in a purposive sample of Australian festival-goers who used ecstasy at the last festival they attended. Design and Methods. A web survey was completed by almost 2000 Australian festivalgoers. The analytic sample (n = 777) was 59% male and had a median age of 20 years (interquartile range 19-23). Results. Almost half (48%) of respondents who used ecstasy pills reported double dropping in association with the last festival attended. Multivariable logistic regression found respondents who were younger, male, more frequent ecstasy users, more frequent festival-goers, had a preference for electronic dance music, attended a multi-day festival and used ecstasy in pill form were at greater odds of reporting double dropping at the last festival attended. Discussion and Conclusions. Double dropping was a commonly reported practice among festival-goers in this purposive sample. While this practice may reflect historically low-dose ecstasy pills in Australia, the changing contexts of novel drugs and increasing MDMA purity may warrant consideration of harm-reduction interventions and drug-checking services which could help festival-goers make more informed decisions about drug dosage. [Grigg J, Barratt MJ, Lenton S. Double dropping down under: Correlates of simultaneous consumption of two ecstasy pills in a sample of Australian outdoor music festival attendees. Drug Alcohol Rev 2018;37:851-855]

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Hidden Populations, Online Purposive Sampling, and External Validity

Cited by 140 publications

References 36 publications

Correlates of new psychoactive substance use among a self-selected sample of nightclub attendees in the United States

Correlates of new psychoactive substance use among a self-selected sample of nightclub attendees in the United States

Randomised controlled trial of silk therapeutic garments for the management of atopic eczema in children: the CLOTHES trial

Double dropping down under: Correlates of simultaneous consumption of two ecstasy pills in a sample of Australian outdoor music festival attendees

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