Understanding and using time series analyses in addiction research

Time series analyses are statistical methods used to assess trends in repeated measurements taken at regular intervals and their associations with other trends or events, taking account of the temporal structure of such data. Addiction research often involves assessing associations between trends in target variables (e.g. population cigarette smoking prevalence) and predictor variables (e.g. average price of a cigarette), known as a multiple time series design, or interventions or events (e.g. introduction of an indoor smoking ban), known as an interrupted time series design. There are many analytical tools available, each with its own strengths and limitations. This paper provides addiction researchers with an overview of many of the methods available (GLM, GLMM, GLS, GAMM, ARIMA, ARIMAX, VAR, SVAR, VECM) and guidance on when and how they should be used, sample size det ermination, reporting and interpretation. The aim is to provide increased clarity for researchers proposing to undertake these analyses concerning what is likely to be acceptable for publication in journals such as Addiction. Given the large number of choices that need to be made when setting up time series models, the guidance emphasizes the importance of pre‐registering hypotheses and analysis plans before the analyses are undertaken.     

Getting back to equal: The influence of insurance status on racial disparities in the treatment of African American men with high-risk prostate cancer

ObjectivesTreating high-risk prostate cancer (CaP) with definitive therapy improves survival. We evaluated whether having health insurance reduces racial disparities in the use of definitive therapy for high-risk CaP.Materials and methodsThe Surveillance, Epidemiology, and End Results Program was used to identify 70,006 men with localized high-risk CaP (prostate-specific antigen level >20 ng/ml or Gleason score 8–10 or stage>cT3a) diagnosed from 2007 to 2010. We used multivariable logistic regression to analyze the 64,277 patients with complete data to determine the factors associated with receipt of definitive therapy.ResultsCompared with white men, African American (AA) men were significantly less likely to receive definitive treatment (adjusted odds ratio [AOR] = 0.60; 95% CI: 0.56–0.64; P<0.001) after adjusting for sociodemographics and known CaP prognostic factors. There was a significant interaction between race and insurance status (P_interaction = 0.01) such that insurance coverage was associated with a reduction in racial disparity between AA and white patients regarding receipt of definitive therapy. Specifically, the AOR for definitive treatment for AA vs. white was 0.38 (95% CI: 0.27–0.54, P<0.001) among uninsured men, whereas the AOR was 0.62 (95% CI: 0.57–0.66, P<0.001) among insured men.ConclusionsAA men with high-risk CaP were significantly less likely to receive potentially life-saving definitive treatment when compared with white men. Having health insurance was associated with a reduction in this racial treatment disparity, suggesting that expansion of health insurance coverage may help reduce racial disparities in the management of aggressive cancers.     

Alvimopan Accelerates Gastrointestinal Recovery After Radical Cystectomy: A Multicenter Randomized Placebo-Controlled Trial

Background

Radical cystectomy (RC) for bladder cancer is frequently associated with delayed gastrointestinal (GI) recovery that prolongs hospital length of stay (LOS).

Objective

To assess the efficacy of alvimopan to accelerate GI recovery after RC.

Design, setting, and participants

We conducted a randomized double-blind placebo-controlled trial in patients undergoing RC and receiving postoperative intravenous patient-controlled opioid analgesics.

Intervention

Oral alvimopan 12 mg (maximum: 15 inpatient doses) versus placebo.

Outcome measurements and statistical analysis

The two-component primary end point was time to upper (first tolerance of solid food) and lower (first bowel movement) GI recovery (GI-2). Time to discharge order written, postoperative LOS, postoperative ileus (POI)-related morbidity, opioid consumption, and adverse events (AEs) were evaluated. An independent adjudication of cardiovascular AEs was performed.

Results and limitations

Patients were randomized to alvimopan (n = 143) or placebo (n = 137); 277 patients were included in the modified intention-to-treat population. The alvimopan cohort experienced quicker GI-2 recovery (5.5 vs 6.8 d; hazard ratio: 1.8; p < 0.0001), shorter mean LOS (7.4 vs 10.1 d; p = 0.0051), and fewer episodes of POI-related morbidity (8.4% vs 29.1%; p < 0.001). The incidence of opioid consumption and AEs or serious AEs (SAEs) was comparable except for POI, which was lower in the alvimopan group (AEs: 7% vs 26%; SAEs: 5% vs 20%, respectively). Cardiovascular AEs occurred in 8.4% (alvimopan) and 15.3% (placebo) of patients (p = 0.09). Generalizability may be limited due to the exclusion of epidural analgesia and the inclusion of mostly high-volume centers utilizing open laparotomy.

Conclusions

Alvimopan is a useful addition to a standardized care pathway in patients undergoing RC by accelerating GI recovery and shortening LOS, with a safety profile similar to placebo.

Patient summary

This study examined the effects of alvimopan on bowel recovery in patients undergoing radical cystectomy for bladder cancer. Patients receiving alvimopan experienced quicker bowel recovery and had a shorter hospital stay compared with those who received placebo, with comparable safety.

Trial registration

ClinicalTrials.gov identifier NCT00708201     

An estimation of inguinal hernia epidemiology adjusted for population age structure in Tanzania

Purpose

Surgical conditions represent a significant source of global disease burden. Little is known about the epidemiology of inguinal hernia in resource-poor settings. We present a method to estimate inguinal hernia disease burden in Tanzania.

Methods

Using data from the United States National Health and Nutrition Examination Survey (NHANES) prospective cohort study and Tanzanian demographic figures, we calculated inguinal hernia incidence and prevalence in Tanzanian adults under three surgical rate scenarios. Gender-specific incidence figures from NHANES data were adjusted according to Tanzanian population age structure. Hernia duration was adjusted for Tanzanian life expectancy within each age group.

Results

The prevalence of inguinal hernia in Tanzanian adults is 5.36 % while an estimated 12.09 % of men had hernias. Today, 683,904 adults suffer from symptomatic inguinal hernia in Tanzania. The annual incidence of symptomatic hernias in Tanzanian adults is 163 per 100,000 population. At Tanzania’s current hernia repair rate, a backlog of 995,874 hernias in need of repair will develop over 10 years. 4.4 million disability-adjusted life-years would be averted with repair of prevalent symptomatic hernias in Tanzania.

Conclusions

Our data indicate the extent of inguinal hernia disease burden in Tanzania. By adjusting our figures for the age structure of Tanzania, we have demonstrated that while the incidence of symptomatic cases may be lower than previously thought, prevalence of inguinal hernia in Tanzania remains high. This approach provides an update to our previously described methodology for calculation of inguinal hernia epidemiology in resource-poor settings that may be used in multiple country contexts.     

Long-Term and Oncologic Outcomes of Robotic Versus Laparoscopic Liver Resection for Metastatic Colorectal Cancer: A Multicenter,Propensity Score Matching Analysis

World Journal of Surgery - To assess long-term oncologic outcomes of robotic-assisted liver resection (RLR) for colorectal cancer (CRC) metastases as compared to a propensity-matched cohort of...     

Socio‐economic impact of Foot‐and‐Mouth Disease outbreaks and control measures: An analysis of Mongolian outbreaks in 2017

Mongolia is a large landlocked country in Central Asia and has one of the highest per capita livestock ratios in the world. During 2017, reported foot‐and‐mouth disease (FMD) outbreaks in Mongolia increased considerably, prompting widespread disease control measures. This study estimates the socio‐economic impact of FMD and subsequent control measures on Mongolian herders. The analysis encompassed quantification of the impact on subsistence farmers’ livelihoods and food security and estimation of the national‐level gross losses due to reaction and expenditure during 2017. Data were collected from 112 herders across eight provinces that reported disease. Seventy of these herders had cases of FMD, while 42 did not have FMD in their animals but were within quarantine zones. Overall, 86/112 herders reported not drinking milk for a period of time and 38/112 reduced their meat consumption. Furthermore, 55 herders (49.1%) had to borrow money to buy food, medicines and/or pay bills or bank loans. Among herders with FMD cases, the median attack rate was 31.7%, 3.8% and 0.59% in cattle, sheep and goats, respectively, with important differences across provinces. Herders with clinical cases before the winter had higher odds of reporting a reduction in their meat consumption. National‐level gross losses due to FMD in 2017 were estimated using government data. The estimate of gross economic loss was 18.4 billion Mongolian‐tugriks (US$7.35 million) which equates to approximately 0.65% of the Mongolian GDP. The FMD outbreaks combined with current control measures have negatively impacted herders’ livelihoods (including herders with and without cases of FMD) which are likely to reduce stakeholder advocacy. Possible strategies that could be employed to ameliorate the negative effects of the current control policy were identified. The findings and approach are relevant to other FMD endemic regions aiming to control the disease.     

跟骨定量超声骨质测量参数与骨密度及骨组织形态计量学指标的关系

目的:分析跟骨定量超声骨质测量中各参数与骨密度及形态计量学指标的相关性。方法:选择2004-01/2005-12广州市第六人民医院和中山大学三院骨科小腿以上截肢患者38例,将其跟骨定量超声测定的超声振幅衰减平均值与健康青年人骨峰值进行比较,>-2.5 SD者为骨量正常组(12例),<-2.5 SD者为骨质疏松组(26例)。分别进行跟骨定量超声、双能X线骨密度测量仪及骨形态计量学测量,应用直线相关分析法分析跟骨定量超声测定中各参数与骨密度及骨组织形态计量学各指标的相关性。结果:38例全部进入结果分析。①骨质疏松组跟骨超声振幅衰减平均值和骨硬度指数值均小于骨量正常组(P<0.01)。②骨量正常组跟骨骨密度值显著高于骨质疏松组[(352±16),(233±14)mg/cm2,P<0.01]。③骨量正常组跟骨平均骨小梁间距或弥散度低于骨质疏松组而松质骨体积高于骨质疏松组(P<0.05)。④超声振幅衰减平均值和骨硬度指数与骨密度呈直线正相关(r=0.814,0.326,P<0.01,0.05)。⑤超声传播速度与骨小梁游离末端、平均骨小梁间距呈直线负相关(r=-0.688,-0.712,P<0.01),与小梁间连点数、松质骨体积呈直线正相关(r=0.672,0.794,P<0.01);骨硬度指数与平均骨小梁间距呈直线负相关(r=-0.358,P<0.05),与松质骨体积呈直线正相关(r=0.513,P<0.01)。结论:跟骨定量超声测量中,超声振幅衰减平均值能较好地反映骨的密度,超声传播速度能较好地反映骨的质量,而骨硬度指数能较综合地反映骨强度的改变。