Clinical and radiological outcomes in patients who underwent posterior lumbar interbody fusion: comparisons between unilateral and bilateral cage insertion.

BACKGROUND: Although the original technique involves inserting two cages bilaterally, there could be situations that only allow for insertion of one cage unilaterally. However, only a few studies have compared the outcomes between unilateral and bilateral cage insertion. The purpose of this study was to compare the clinical and radiological outcomes in patients who underwent posterior lumbar interbody fusion (PLIF) between unilaterally and bilaterally inserted cages. METHODS: Among 206 eligible patients who underwent 1- or 2-level PLIF, 78 patients were 1:3 cohort-matched by age, sex, and operation level (group U, 19 patients with unilateral cages; and group B, 57 patients with bilateral cages). Fusion status was evaluated by computed tomography (CT) scans at postoperative 1 year. Clinical outcomes were measured by visual analog scale (VAS), Oswestry Disability Index (ODI), and EQ-5D. Radiological and clinical parameters were compared between the two groups. Risk factors for pseudarthrosis were also analyzed by multivariate analysis. RESULTS: The demographic data were not significantly different between the two groups. However, previous laminectomy, asymmetric disc collapse, and fusion at L5-S1 level were more frequently found in group U (P = 0.003, P = 0.014, and P = 0.014, respectively). Furthermore, pseudarthrosis was more frequently observed in group U (36.8%) than in group B (7.0%) (P = 0.004). Back pain VAS was higher in group U at postoperative 1 year (P = 0.033). Lower general activity function of EQ-5D was observed in group U at postoperative 1 year (P = 0.035). Older age (P = 0.028), unilateral cage (P = 0.007), and higher bone mineral density (P = 0.033) were positively correlated with pseudarthrosis. CONCLUSIONS: Unilaterally inserted cage might be a possible risk factor for pseudarthrosis when performing PLIF, which could be related with the difficult working conditions such as scars due to previous laminectomy or asymmetric disc collapse. Furthermore, suboptimal clinical outcomes are expected following PLIF with unilateral cage insertion at postoperative 1 year regardless of similar clinical outcomes at postoperative 2 year. Therefore, caution is advised when inserting cages unilaterally, especially under above-mentioned conditions in terms of its possible relationship with symptomatic pseudarthrosis.

Population scale latent space cohort matching for the improved use and exploration of observational trial data.

A significant amount of clinical research is observational by nature and derived from medical records, clinical trials, and large-scale registries. While there is no substitute for randomized, controlled experimentation, such experiments or trials are often costly, time consuming, and even ethically or practically impossible to execute. Combining classical regression and structural equation modeling with matching techniques can leverage the value of observational data. Nevertheless, identifying variables of greatest interest in high-dimensional data is frequently challenging, even with application of classical dimensionality reduction and/or propensity scoring techniques. Here, we demonstrate that projecting high-dimensional medical data onto a lower-dimensional manifold using deep autoencoders and post-hoc generation of treatment/control cohorts based on proximity in the lower-dimensional space results in better matching of confounding variables compared to classical propensity score matching (PSM) in the original high-dimensional space (P<0.0001) and performs similarly to PSM models constructed by experts with prior knowledge of the underlying pathology when evaluated on predicting risk ratios from real-world clinical data. Thus, in cases when the underlying problem is poorly understood and the data is high-dimensional in nature, matching in the autoencoder latent space might be of particular benefit.

Comparison of the effect of caseload midwifery program and standard midwifery-led care on primiparous birth outcomes: A retrospective cohort matching study.

BACKGROUND: The effectiveness of continuity of care during the perinatal period is well documented, but implementing continuity of care model to practice requires evaluation. AIM: To evaluate the effect of a caseload midwifery program (CMP) on birth outcomes and rates of perinatal interventions at a metropolitan tertiary hospital in Australia, compared with standard midwifery-led care (SMC). METHODS: This was a retrospective, matched-cohort study. We extracted the data of 1000 nulliparous women from records of 19,001 women who gave birth at the hospital from 2011 to 2014. We used basic statistical tests to compare baseline demographic data, and logistic regression to calculate odds ratios, to evaluate maternal and neonatal outcomes. RESULTS: Adjusted regression analysis for the primary outcome showed that compared with women who received SMC, women who received care through CMP had an increased rate of normal vaginal birth (69% vs. 50%, OR = 1.79, 95%, CI = 1.38-2.32). Assessment of secondary outcomes showed that the women in CMP group had decreased rates of instrumental birth (15% vs. 26%, OR = 0.48, 95% CI = 0.35-0.66), episiotomy (23% vs. 40%, OR = 0.43, 95% CI = 0.33-0.57), epidural analgesia (33% vs. 43%, OR = 0.64, 95% CI = 0.50-0.83) and amniotomy (35% vs. 50%, OR = 0.56, 95% CI = 0.43-0.72). The CMP group also had greater rates of water immersion (54% vs. 22%, OR = 4.18, 95% CI = 3.17-5.5), physiological 3rd stage (7% vs. 1%, OR = 11.71, 95% CI = 3.56-38.43) and 2nd degree tear (34% vs. 24%, OR = 1.60, 95% CI = 1.21-2.11). There were no significant differences between the two groups for rates of other secondary outcomes including Caesarean section, cervical ripening procedures, third- and fourth-degree tears, postpartum haemorrhage and neonatal outcomes. CONCLUSION: CMP care is associated with increased rate of normal vaginal birth which supports wider implementation of the model. In addition, using routinely collected data and a cohort matching design can be an effective approach to evaluate maternal and neonatal outcomes.