Population Mobility Trends, Deprivation Index and the Spatio-Temporal Spread of Coronavirus Disease 2019 in Ireland.

Like most countries worldwide, the coronavirus disease (COVID-19) has adversely affected Ireland. The aim of this study was to (i) investigate the spatio-temporal trend of COVID-19 incidence; (ii) describe mobility trends as measured by aggregated mobile phone records; and (iii) investigate the association between deprivation index, population density and COVID-19 cases while accounting for spatial and temporal correlation. Standardised incidence ratios of cases were calculated and mapped at a high spatial resolution (electoral division level) over time. Trends in the percentage change in mobility compared to a pre-COVID-19 period were plotted to investigate the impact of lockdown restrictions. We implemented a hierarchical Bayesian spatio-temporal model (Besag, York and Mollié (BYM)), commonly used for disease mapping, to investigate the association between covariates and the number of cases. There have been three distinct "waves" of COVID-19 cases in Ireland to date. Lockdown restrictions led to a substantial reduction in human movement, particularly during the 1st and 3rd wave. Despite adjustment for population density (incidence ratio (IR) = 1.985 (1.915-2.058)) and the average number of persons per room (IR = 10.411 (5.264-22.533)), we found an association between deprivation index and COVID-19 incidence (IR = 1.210 (CI: 1.077-1.357) for the most deprived quintile compared to the least deprived). There is a large range of spatial heterogeneity in COVID-19 cases in Ireland. The methods presented can be used to explore locally intensive surveillance with the possibility of localised lockdown measures to curb the transmission of infection, while keeping other, low-incidence areas open. Our results suggest that prioritising densely populated deprived areas (that are at increased risk of comorbidities) during vaccination rollout may capture people that are at risk of infection and, potentially, also those at increased risk of hospitalisation.

Methadone dosing and prescribed medication use in a prospective cohort of opioid-dependent pregnant women.

AIMS: This study aimed to (i) describe methadone dosing before, during and after pregnancy, (ii) to compare the incidence of neonatal abstinence syndrome (NAS) between those with dose decreases and those with steady or increasing doses and (iii) to describe prescribed medication use among opioid-dependent pregnant women. DESIGN: Prospective cohort study. SETTING: Two Irish tertiary care maternity hospitals. PARTICIPANTS: A total of 117 pregnant women on methadone maintenance treatment (MMT) recruited between July 2009 and July 2010. MEASUREMENTS: Electronic dispensing records from addiction clinics and the Primary Care Reimbursement Service were used to determine methadone doses and dispensed medications in the year preceding and the month following delivery. The Finnegan score was used to determine need for medical treatment of NAS. FINDINGS: Of the 117 participants, sufficient dosing data were available for 89 women treated with MMT throughout pregnancy; 36 (40.4%) had their dose decreased from a mean pre-pregnancy dose of 73.3 mg [standard deviation (SD) 25.5] to a third-trimester dose of 58.0 mg (SD 26.0). The corresponding figures for those with increased doses (n = 31, 34.8%) were 70.7 mg (SD 25.3) and 89.7 mg (SD 21.0), respectively. The incidence of medically treated NAS did not differ between dosage groups. Antidepressants were dispensed for 29 women (25.7%) during pregnancy, with the rate decreasing from pre-pregnancy to postpartum. Benzodiazepines were prescribed for 43 women (38.0%). CONCLUSION: In the Irish health service, opioid-dependent women frequently have their methadone dose decreased during pregnancy but this does not appear to affect the incidence of the neonatal abstinence syndrome in their babies.

Methadone and perinatal outcomes: a prospective cohort study.

AIMS: Methadone use in pregnancy has been associated with adverse perinatal outcomes and neonatal abstinence syndrome (NAS). This study aimed to examine perinatal outcomes and NAS in relation to (i) concomitant drug use and (ii) methadone dose. DESIGN: Prospective cohort study. SETTING: Two tertiary care maternity hospitals. PARTICIPANTS: A total of 117 pregnant women on methadone maintenance treatment recruited between July 2009 and July 2010. MEASUREMENTS: Information on concomitant drug use was recorded with the Addiction Severity Index. Perinatal outcomes included pre-term birth (<37 weeks' gestation), small-for-gestational-age (<10th centile) and neonatal unit admission. NAS outcomes included: incidence of medically treated NAS, peak Finnegan score, cumulative dose of NAS treatment and duration of hospitalization. FINDINGS: Of the 114 liveborn infants 11 (9.6%) were born pre-term, 49 (42.9%) were small-for-gestational-age, 56 (49.1%) had a neonatal unit admission and 29 (25.4%) were treated medically for NAS. Neonates exposed to methadone-only had a shorter hospitalization than those exposed to methadone and concomitant drugs (median 5.0 days versus 6.0 days, P = 0.03). Neonates exposed to methadone doses ≥80 mg required higher cumulative doses of morphine treatment for NAS (median 13.2 mg versus 19.3 mg, P = 0.03). The incidence and duration of NAS did not differ between the two dosage groups. CONCLUSIONS: The incidence and duration of the neonatal abstinence syndrome is not associated with maternal methadone dose, but maternal opiate, benzodiazepine or cocaine use is associated with longer neonatal hospitalization.