ZLZhixin Liu

Zhixin Liu

*This is an algorithmically generated author record based on publicly available information.

Zhixin Liu has a total of 79 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Effect of a Smartphone App (S-Check) on Actual and Intended Help-Seeking and Motivation to Change Methamphetamine Use Among Adult Consumers of Methamphetamine in Australia: Randomized Waitlist-Controlled Trial

    by Krista J Siefried, Florence Bascombe, Brendan Clifford, Zhixin Liu, Peter Middleton, Frances Kay-Lambkin, Jack Freestone, Daniel Herman, Michael Millard, Maureen Steele, et al.

    Background: Interventions are required that address delays in treatment-seeking and low treatment coverage among people consuming methamphetamine. Objective: We aim to determine whether a self-administered smartphone-based intervention, the “S-Check app” can increase help-seeking and motivation to change methamphetamine use, and determine factors associated with app engagement. Methods: This study is a randomized, 28-day waitlist-controlled trial. Consenting adults residing in Australia who reported using methamphetamine at least once in the last month were eligible to download the app for free from Android or iOS app stores. Those randomized to the intervention group had immediate access to the S-Check app, the control group was wait-listed for 28 days before gaining access, and then all had access until day 56. Actual help-seeking and intention to seek help were assessed by the modified Actual Help Seeking Questionnaire (mAHSQ), modified General Help Seeking Questionnaire, and motivation to change methamphetamine use by the modified readiness ruler. χ2 comparisons of the proportion of positive responses to the mAHSQ, modified General Help Seeking Questionnaire, and modified readiness ruler were conducted between the 2 groups. Logistic regression models compared the odds of actual help-seeking, intention to seek help, and motivation to change at day 28 between the 2 groups. Secondary outcomes were the most commonly accessed features of the app, methamphetamine use, feasibility and acceptability of the app, and associations between S-Check app engagement and participant demographic and methamphetamine use characteristics. Results: In total, 560 participants downloaded the app; 259 (46.3%) completed eConsent and baseline; and 84 (32.4%) provided data on day 28. Participants in the immediate access group were more likely to seek professional help (mAHSQ) at day 28 than those in the control group (n=15, 45.5% vs n=12, 23.5%; χ21=4.42, P=.04). There was no significant difference in the odds of actual help-seeking, intention to seek help, or motivation to change methamphetamine use between the 2 groups on the primary logistic regression analyses, while in the ancillary analyses, the imputed data set showed a significant difference in the odds of seeking professional help between participants in the immediate access group compared to the waitlist control group (adjusted odds ratio 2.64, 95% CI 1.19-5.83, P=.02). For participants not seeking help at baseline, each minute in the app increased the likelihood of seeking professional help by day 28 by 8% (ratio 1.08, 95% CI 1.02-1.22, P=.04). Among the intervention group, a 10-minute increase in app engagement time was associated with a decrease in days of methamphetamine use by 0.4 days (regression coefficient [β] –0.04, P=.02). Conclusions: The S-Check app is a feasible low-resource self-administered intervention for adults in Australia who consume methamphetamine. Study attrition was high and, while common in mobile health interventions, warrants larger studies of the S-Check app. Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12619000534189; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377288&isReview=true


  • Open Access

    Effect of a Smartphone App (S-Check) on Actual and Intended Help-Seeking and Motivation to Change Methamphetamine Use Among Adult Consumers of Methamphetamine in Australia: Randomized Waitlist-Controlled Trial (Preprint)

    by Krista J Siefried, Florence Bascombe, Brendan Clifford, Zhixin Liu, Peter Middleton, Frances Kay-Lambkin, Jack Freestone, Daniel Herman, Michael Millard, Maureen Steele, et al.

    BACKGROUND Interventions are required that address delays in treatment-seeking and low treatment coverage among people consuming methamphetamine. OBJECTIVE We aim to determine whether a self-administered smartphone-based intervention, the “S-Check app” can increase help-seeking and motivation to change methamphetamine use, and determine factors associated with app engagement. METHODS This study is a randomized, 28-day waitlist-controlled trial. Consenting adults residing in Australia who reported using methamphetamine at least once in the last month were eligible to download the app for free from Android or iOS app stores. Those randomized to the intervention group had immediate access to the S-Check app, the control group was wait-listed for 28 days before gaining access, and then all had access until day 56. Actual help-seeking and intention to seek help were assessed by the modified Actual Help Seeking Questionnaire (mAHSQ), modified General Help Seeking Questionnaire, and motivation to change methamphetamine use by the modified readiness ruler. χ2 comparisons of the proportion of positive responses to the mAHSQ, modified General Help Seeking Questionnaire, and modified readiness ruler were conducted between the 2 groups. Logistic regression models compared the odds of actual help-seeking, intention to seek help, and motivation to change at day 28 between the 2 groups. Secondary outcomes were the most commonly accessed features of the app, methamphetamine use, feasibility and acceptability of the app, and associations between S-Check app engagement and participant demographic and methamphetamine use characteristics. RESULTS In total, 560 participants downloaded the app; 259 (46.3%) completed eConsent and baseline; and 84 (32.4%) provided data on day 28. Participants in the immediate access group were more likely to seek professional help (mAHSQ) at day 28 than those in the control group (n=15, 45.5% vs n=12, 23.5%; χ21=4.42, P=.04). There was no significant difference in the odds of actual help-seeking, intention to seek help, or motivation to change methamphetamine use between the 2 groups on the primary logistic regression analyses, while in the ancillary analyses, the imputed data set showed a significant difference in the odds of seeking professional help between participants in the immediate access group compared to the waitlist control group (adjusted odds ratio 2.64, 95% CI 1.19-5.83, P=.02). For participants not seeking help at baseline, each minute in the app increased the likelihood of seeking professional help by day 28 by 8% (ratio 1.08, 95% CI 1.02-1.22, P=.04). Among the intervention group, a 10-minute increase in app engagement time was associated with a decrease in days of methamphetamine use by 0.4 days (regression coefficient [β] –0.04, P=.02). CONCLUSIONS The S-Check app is a feasible low-resource self-administered intervention for adults in Australia who consume methamphetamine. Study attrition was high and, while common in mobile health interventions, warrants larger studies of the S-Check app. CLINICALTRIAL Australian New Zealand Clinical Trials Registry ACTRN12619000534189; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377288&isReview=true

  • Open Access

    The MothersBabies Study, an Australian Prospective Cohort Study Analyzing the Microbiome in the Preconception and Perinatal Period to Determine Risk of Adverse Pregnancy, Postpartum, and Child-Related Health Outcomes: Study Protocol

    by Naomi Strout, Lana Pasic, Chloe Hicks, Xin-Yi Chua, Niki Tashvighi, Phoebe Butler, Zhixin Liu, Fatima El-Assaad, Elaine Holmes, Daniella Susic, et al.

    The microbiome has emerged as a key determinant of human health and reproduction, with recent evidence suggesting a dysbiotic microbiome is implicated in adverse perinatal health outcomes. The existing research has been limited by the sample collection and timing, cohort design, sample design, and lack of data on the preconception microbiome. This prospective, longitudinal cohort study will recruit 2000 Australian women, in order to fully explore the role of the microbiome in the development of adverse perinatal outcomes. Participants are enrolled for a maximum of 7 years, from 1 year preconception, through to 5 years postpartum. Assessment occurs every three months until pregnancy occurs, then during Trimester 1 (5 + 0–12 + 6 weeks gestation), Trimester 2 (20 + 0–24 + 6 weeks gestation), Trimester 3 (32 + 0–36 + 6 weeks gestation), and postpartum at 1 week, 2 months, 6 months, and then annually from 1 to 5 years. At each assessment, maternal participants self-collect oral, skin, vaginal, urine, and stool samples. Oral, skin, urine, and stool samples will be collected from children. Blood samples will be obtained from maternal participants who can access a study collection center. The measurements taken will include anthropometric, blood pressure, heart rate, and serum hormonal and metabolic parameters. Validated self-report questionnaires will be administered to assess diet, physical activity, mental health, and child developmental milestones. Medications, medical, surgical, obstetric history, the impact of COVID-19, living environments, and pregnancy and child health outcomes will be recorded. Multiomic bioinformatic and statistical analyses will assess the association between participants who developed high-risk and low-risk pregnancies, adverse postnatal conditions, and/or childhood disease, and their microbiome for the different sample types.


  • Open Access

    A Retrospective Medical Record Review of Adults with Non-Cancer Diagnoses Prescribed Medicinal Cannabis

    by Michael Morris, Richard Chye, Zhixin Liu, Meera Agar, Valentina Razmovski-Naumovski

    Research describing patients using medicinal cannabis and its effectiveness is lacking. We aimed to describe adults with non-cancer diagnoses who are prescribed medicinal cannabis via a retrospective medical record review and assess its effectiveness and safety. From 157 Australian records, most were female (63.7%; mean age 63.0 years). Most patients had neurological (58.0%) or musculoskeletal (24.8%) conditions. Medicinal cannabis was perceived beneficial by 53.5% of patients. Mixed-effects modelling and post hoc multiple comparisons analysis showed significant changes overtime for pain, bowel problems, fatigue, difficulty sleeping, mood, quality of life (all p < 0.0001), breathing problems (p = 0.0035), and appetite (p = 0.0465) Symptom Assessment Scale scores. For the conditions, neuropathic pain/peripheral neuropathy had the highest rate of perceived benefit (66.6%), followed by Parkinson’s disease (60.9%), multiple sclerosis (60.0%), migraine (43.8%), chronic pain syndrome (42.1%), and spondylosis (40.0%). For the indications, medicinal cannabis had the greatest perceived effect on sleep (80.0%), followed by pain (51.5%), and muscle spasm (50%). Oral oil preparations of balanced delta-9-tetrahydrocannabinol/cannabidiol (average post-titration dose of 16.9 mg and 34.8 mg per day, respectively) were mainly prescribed. Somnolence was the most frequently reported side effect (21%). This study supports medicinal cannabis’ potential to safely treat non-cancer chronic conditions and indications.


  • Open Access

    Cognitive impairment in psychiatric diseases: Biomarkers of diagnosis, treatment, and prevention

    by Yafen Wang, Weicheng Meng, Zhixin Liu, Qunxing An, Xingbin Hu

    Psychiatric diseases, such as schizophrenia, bipolar disorder, autism spectrum disorder, and major depressive disorder, place a huge health burden on society. Cognitive impairment is one of the core characteristics of psychiatric disorders and a vital determinant of social function and disease recurrence in patients. This review thus aims to explore the underlying molecular mechanisms of cognitive impairment in major psychiatric disorders and identify valuable biomarkers for diagnosis, treatment and prevention of patients.


  • Top Cited Papers
    Open Access

    Intrinsic Capacity: Validation of a New WHO Concept for Healthy Aging in a Longitudinal Chinese Study

    by John R Beard, Yafei Si, Zhixin Liu, Lynn Chenoweth, Katja Hanewald

    The World Health Organization has proposed a model of healthy aging built around the concept of functional ability, comprising an individual’s intrinsic capacity, the physical and social environment they occupy, and interactions between the two. However, these constructs have been poorly defined. We examined the structure of intrinsic capacity in a representative sample of the Chinese population aged 60 years and older and assessed its value in predicting declining performance in instrumental activities of daily living (IADLs) and activities of daily living (ADLs) using similar methods to a construct validation previously undertaken in an English cohort. Deidentified data were accessed on 7 643 participants of the China Health and Retirement Longitudinal Study 2011 and 2013 waves. Incrementally related structural equation modeling was applied, including exploratory and confirmatory factor analysis, and path analysis. Multiple linear regression tested construct validity, and simple and serial mediation models assessed predictive validity. Factor loadings for the models showed a clear structure for intrinsic capacity: 1 general factor with 5 subfactors—locomotor, cognitive, psychological and sensory capacities, and vitality (reflecting underlying physiologic changes). Intrinsic capacity predicted declining performance in both IADLs (standardized coefficient (SE) −0.324 (0.02), p < .001) and ADLs (−0.227 (0.03), p < .001), after accounting for age, sex, education, wealth, and number of chronic diseases. Each characteristic was associated with intrinsic capacity, providing strong construct validity. Assessment of intrinsic capacity provides valuable information on an individual’s subsequent functioning beyond that afforded by age, other personal factors, and multimorbidity.


  • Medical diagnosis at the point-of-care by portable high-field asymmetric waveform ion mobility spectrometry: a systematic review and meta-analysis

    by J. Diana Zhang, Merryn J. Baker, Zhixin Liu, K. M. Mohibul Kabir, Vijaya B. Kolachalama, Deborah H. Yates, William A Donald

    Non-invasive medical diagnosis by analysing volatile organic compounds (VOCs) at the point-of-care is becoming feasible owing to recent advances in portable instrumentation. A number of studies have assessed the performance of a state-of-the-art VOC analyser (micro-chip high-field asymmetric waveform ion mobility spectrometry, FAIMS) for medical diagnosis. However, a comprehensive meta-analysis is needed to investigate the overall diagnostic performance of these novel methods across different medical conditions. An electronic search was performed using the CAplus and MEDLINE database through the SciFinder platform. The review identified a total of 23 studies and 2312 individuals. Eighteen studies were used for meta-analysis. A pooled analysis found an overall sensitivity of 80% (95% CI, 74%–85%, I 2 = 62%), and specificity of 78% (95% CI, 70%–84%, I 2 = 80%), which corresponds to the overall diagnostic performance of micro-chip FAIMS across many different medical conditions. The diagnostic accuracy was particularly high for coeliac and inflammatory bowel disease (sensitivity and specificity from 74% to 97%). The overall diagnostic performance was similar across breath, urine, and faecal matrices with sparse logistic regression and random forests algorithms resulting in higher diagnostic accuracy. Sources of variability likely arise from differences in sample storage, sampling protocol, method of data analysis, type of disease, sample matrix, and potentially to clinical and disease factors. The results of this meta-analysis indicate that micro-chip FAIMS is a promising candidate for disease screening at the point-of-care, particularly for gastroenterology diseases. This review provides recommendations that should improve the techniques relevant to diagnostic accuracy of future VOC and point-of-care studies.


  • Open Access

    Safety and tolerability of oral lisdexamfetamine in adults with methamphetamine dependence: a phase-2 dose-escalation study

    by Nadine Ezard, Brendan Clifford, Adrian Dunlop, Raimondo Bruno, Andrew Carr, Zhixin Liu, Krista J Siefried, Nicholas Lintzeris

    Objectives To examine the safety of an agonist-type treatment, lisdexamfetamine (LDX), at 250 mg/day among adults with methamphetamine (MA) dependence. Design A dose-escalating, phase-2, open-label, single-group study of oral LDX at two Australian drug treatment services. Setting The study was conducted at two Australian stimulant use disorder treatment clinics. Participants There were 16 participants: at least 18 years old, MA dependent for at least the preceding 2 years using ICD-10 criteria, reporting use of MA on at least 14 of the preceding 28 days. Interventions Daily, supervised LDX of 100–250 mg, single-blinded to dose, ascending-descending regimen over 8 weeks (100–250 mg over 4 weeks; followed by 4-week dose reduction regimen, 250–100 mg). Participants were followed through to week 12. Outcomes Primary outcomes were safety, drug tolerability and regimen completion at the end of week 4. Participants were followed to week 12. Secondary outcomes included: change in MA use; craving; withdrawal; severity of dependence; risk behaviour; change in other substance use; medication acceptability; potential for non-prescription use; adherence and neurocognitive functioning. Results Fourteen of 16 participants (87.5%) completed escalation to 250 mg/day. Two participants withdrew from the trial in the first week: one relocated away from the study site, the other self-withdrew due to a possible, known side effect of LDX (agitation). There was one serious adverse event of suicidal ideation which resolved. All other adverse events were mild or moderate in severity and known side effects of LDX. No participant was withdrawn due to adverse events. MA use decreased from a median of 21 days (IQR: 16–23) to 13 days (IQR: 11–17) over the 4-week escalation period (p=0.013). Conclusions LDX at a dose of up to 250 mg/day was safe and well tolerated by study participants, warranting larger trials as a pharmacotherapy for MA dependence. Trial registration number ACTRN12615000391572.


  • Insulin resistance in type 1 diabetes managed with metformin (INTIMET): Study protocol of a double‐blind placebo‐controlled, randomised trial

    by Jennifer R. Snaith, Dorit Samocha‐Bonet, Jennifer Evans, Zhixin Liu, Greg Kowalski, Clinton Bruce, Deborah J. Holmes‐Walker, Jerry R. Greenfield

    Background: Insulin resistance is an under‐recognised metabolic defect and cardiovascular risk factor in Type 1 diabetes. Whether metformin improves hepatic, muscle or adipose tissue insulin sensitivity has not been studied in adults with Type 1 diabetes. We initiated the INTIMET study (INsulin resistance in Type 1 diabetes managed with METformin), a double‐blind randomised, placebo‐controlled trial to measure the effect of metformin on tissue‐specific insulin resistance in adults with Type 1 diabetes.Methods: We will study 40 adults aged 20–55 years with Type 1 diabetes (HbA1c 80 mmol/mol [9.5%], fasting C‐peptide <0.3 nmol/L) and 20 age‐, gender‐ and body mass index (BMI)‐matched controls. Insulin sensitivity will be determined by the two‐step hyperinsulinaemic‐euglycaemic clamp method with deuterated glucose to document liver, muscle and adipose insulin sensitivity. Subjects with Type 1 diabetes will be randomised to metformin extended‐release 1500 mg daily or matched placebo for 26 weeks. The primary outcome is change in hepatic insulin sensitivity, assessed by change in basal rate of appearance (Ra) of glucose and suppression of endogenous glucose production (EGP) during the low‐dose stage of the clamp.Conclusion: The INTIMET study is the first clinical trial to quantify the impact of metformin on liver, muscle and adipose insulin resistance in adults with Type 1 diabetes. This study may identify factors that predict an individual's response to metformin in Type 1 diabetes. Trial Registration: ACTRN12619001440112.


  • Open Access

    Cognitive ageing is premature among a community sample of optimally treated people living with HIV

    by Hl Aung, M Bloch, T Vincent, D Quan, A Jayewardene, Z Liu, Tm Gates, B Brew, L Mao, LA Cysique

    Objectives: Evidence of premature cognitive ageing amongst people living with HIV (PLHIV) remains controversial due to previous research limitations including underpowered studies, samples with suboptimal antiretroviral access, varying rate of virological control, high rate of AIDS, over‐representation of non‐community samples, and inclusion of inappropriate controls. The current study addresses these limitations, while also considering mental health and non‐HIV comorbidity burden to determine whether PLHIV showed premature cognitive ageing compared with closely comparable HIV‐negative controls.Methods: This study enrolled 254 PLHIV [92% on antiretroviral therapy; 84% with HIV RNA < 50 copies/mL; 15% with AIDS) and 72 HIV‐negative gay and bisexual men [mean (SD) age = 49 (10.2) years] from a single primary care clinic in Sydney, Australia. Neurocognitive function was evaluated with the Cogstate Computerized Battery (CCB) at baseline and 6 months after. Linear mixed‐effects (LME) models examined main and interaction effects of HIV status and chronological age on the CCB demographically uncorrected global neurocognitive z‐score (GZS), adjusting for repeated testing, and then adjusting sequentially for HIV disease markers, mental health and comorbidities.Results: HIV status and age interacted with a lower GZS (β = −0.43, P < 0.05). Higher level of anxiety symptoms (β = −0.11, P < 0.01), historical AIDS (β = −0.12, P < 0.05) and historical HIV brain involvement (β = −0.12, P < 0.05) were associated with lower GZS.Conclusions: We found a robust medium‐sized premature ageing effect on cognition in a community sample with optimal HIV care. Our study supports routine screening of cognitive and mental health among PLHIV aged ≥ 50 years.