Threshold analysis is a novel statistical approach which can be used to investigate which direct comparisons in a network meta-analysis (NMA) have estimated relative effects that may not be robust to changes in the evidence, either due to possible bias, sampling variation, or relevance.

In a health technology assessment of the clinical effectiveness of ablative and non-invasive therapies for patients with early hepatocellular carcinoma (HCC), we conducted a threshold analysis to identify treatment comparisons that would be sensitive to changes in the randomized controlled trial (RCT) evidence used in the NMAs, potentially leading to a change in the recommended treatment. The results of the threshold analysis were used to guide a targeted systematic review of high-quality, non-randomized, prospective comparative studies that could strengthen the evidence for those comparisons identified as sensitive to change.

We conducted NMAs of RCT evidence for four outcomes: overall survival (16 RCTs), progression-free survival (6 RCTs), overall recurrence (7 RCTs), and local recurrence (10 RCTs). The results of the NMAs displayed a high level of uncertainty, attributable to the sparse nature of the network, characterised by interventions being mainly compared in small trials. A targeted systematic review was conducted on relevant interventions that were identified as being sensitive to changes in evidence by the threshold analysis. The studies identified in this review were incorporated into a second NMA to support the RCT evidence.

Threshold analysis has been typically used as a tool to assess how robust comparisons in an NMA are to additional sources of evidence, but it can also be used to guide the search for additional non-randomized evidence when the available RCT evidence is sparse.

Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools.

To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics.

Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts.

Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (β = −0.34 years, s.e. = 0.08), major depression (β = −0.34 years, s.e. = 0.08), schizophrenia (β = −0.39 years, s.e. = 0.08), and educational attainment (β = −0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO.

AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses.

Children reared in institutions experience profound deprivation that is associated with both heightened levels of psychopathology and deficits in executive functioning (EF). It is unclear whether deficits in EF among institutionally-reared children serve as a vulnerability factor that increases risk for later psychopathology. It is also unclear whether this putative association between EF and psychopathology is transdiagnostic (i.e. cuts across domains of psychopathology), or specific to a given syndrome. Thus, we examined whether global deficits in EF mediate the association between severe childhood neglect and general v. specific psychopathology in adolescence.

The sample consisted of 188 children from the Bucharest Early Intervention Project, a longitudinal study examining the brain and behavioral development of children reared in Romanian institutions and a comparison group of never-institutionalized children. EF was assessed at age 8, 12, and 16 using a well-validated measure of neuropsychological functioning. Psychopathology was measured as general (P) and specific internalizing (INT) and externalizing (EXT) factors at age 12 and 16.

Institutionally-reared children had lower global EF and higher general psychopathology (P) at all ages compared to never-institutionalized children. Longitudinal path analysis revealed that the effect of institutionalization on P at age 16 operated indirectly through poorer EF from ages 8 to 12. No indirect effects involving EF were observed for INT or EXT at age 16.

We conclude that stable, global deficits in EF serve as a cognitive endophenotype that increases transdiagnostic vulnerability to psychopathology in adolescence among those who have experienced profound early neglect.

Schizophrenia affects 1% of the population. Clozapine is the only medication licensed for treatment-resistant schizophrenia and is intensively monitored to prevent harm from neutropenia. Clozapine is also associated with increased risk of pneumonia although the mechanism is poorly understood.

To investigate the potential association between clozapine and antibody deficiency.

Patients taking clozapine and patients who were clozapine-naive and receiving alternative antipsychotics were recruited and completed a lifestyle, medication and infection-burden questionnaire. Serum total immunoglobulins (immunoglobulin (Ig)G, IgA, IgM) and specific IgG antibodies to haemophilus influenzae type B, tetanus and IgG, IgA and IgM to pneumococcus were measured.

Immunoglobulins were all significantly reduced in the clozapine-treated group (n = 123) compared with the clozapine-naive group (n = 111). Odds ratios (ORs) for a reduction in clozapine:control immunoglobulin values below the fifth percentile were IgG, OR = 6.00 (95% CI 1.31–27.44); IgA, OR = 16.75 (95% CI 2.18–128.60); and IgM, OR = 3.26 (95% CI 1.75–6.08). These findings remained significant despite exclusion of other potential causes of hypogammaglobulinaemia. In addition, duration on clozapine was associated with decline in IgG. A higher proportion of the clozapine-treated group reported taking more than five courses of antibiotics in the preceding year (5.3% (n = 5) versus 1% (n = 1).

Clozapine use was associated with significantly reduced immunoglobulin levels and an increased proportion of patients using more than five antibiotic courses in a year. Antibody testing is not included in existing clozapine monitoring programmes but may represent a mechanistic explanation and modifiable risk factor for the increased rates of pneumonia and sepsis-related mortality previously reported in this vulnerable cohort.

S.J. has received support from CSL Behring, Shire, LFB, Biotest, Binding Site, Sanofi, GSK, UCB Pharma, Grifols, BPL SOBI, Weatherden, Zarodex and Octapharma for projects, advisory boards, meetings, studies, speaker and clinical trials.

Multidrug-resistant (MDR) Acinetobacter baumannii and Pseudomonas aeruginosa have emerged as the causes of nosocomial infections in critically ill patients.

To characterize the incidence of these MDR bacteria over time in the military healthcare system, comparing isolates recovered from overseas combat casualties with isolates recovered from local military and civilian patients.

Retrospective electronic records review of culture and/or susceptibility testing results of patients admitted to a military level I trauma center in San Antonio, Texas, during the period from January 2001 through December 2008. Multidrug resistance was defined as the first isolated organism resistant to 3 or more classes of antimicrobial agents.

Over time, the percentage of MDR A. baumannii isolates increased from 4% to 55%, whereas the percentage of MDR P. aeruginosa isolates increased from 2% to 8%. Respiratory tract specimens had a higher percentage of MDR A. baumannii isolates (49%), compared with specimens obtained from blood (30%), wound sites (24%), or urine (19%). No difference in the percentages of MDR P. aeruginosa isolates was observed with regard to source of specimen. The percentage of MDR A. baumannii isolates recovered was higher among patients who had been deployed overseas (52%) than among local patients (20%). When isolates recovered from patients in the burn intensive care unit (53% of MDR A. baumannii isolates) were removed from analysis, the percentage of MDR A. baumannii isolates decreased from 38% to 30% while the percentage of MDR P. aeruginosa isolates remained unaffected.

The percentage of MDR A. baumannii isolates increased in this facility among combat casualties and among local patients, which indicates nosocomial transmission; however, there was no significant increase in the percentage of MDR P. aeruginosa isolates. Isolated changes in the MDR pathogens within a facility can occur. Possible interventions to limit the spread of these organisms could include implementing aggressive infection control practices, controlling antibiotic use, and using active culture surveillance.