The relationship between obesity and oral-health status in North African adults: A comparative study.

INTRODUCTION: The strength of the association between obesity and oral health is still indecisive. OBJECTIVE: The objectives of the study were to compare some oral-health data between two groups involving obese (OG) and normal weight (NWG) participants and determine the influencing factors of the periodontal probing depth (PPD). METHODS: This was a cross-sectional study including 67 Tunisian adults [OG (n = 33, body mass index (BMI) > 30 kg/m2 ), NWG (n = 34, BMI: 18.5-25.0 kg/m2 )]. The plaque level was recorded using the plaque index (PI). Gingival index (GI) was used to evaluate gingival inflammation. The depths of the sulci/pockets were probed using a periodontal probe. Stimulated saliva was collected for 5 min, and salivary flow rate (SFR) was determined. Salivary baseline pH (SBpH) was measured. A multivariable regression analysis was performed between PPD and some independent variables [i.e. obesity status, age, sex, socioeconomic status, systemic diseases and PI data]. RESULTS: The OG and NWG were age- and sex-matched and included comparable percentages of participants with systemic diseases (27.3 vs. 29.4%, respectively). The OG included a higher percentage of participants having a low socioeconomic status (87.9 vs. 64.7%, respectively). Compared with the NWG, the OG: (i) had comparable values of daily toothbrushing frequency, PI, GI and tooth mobility, (ii) included comparable percentages of irregular brushers, of participants with periodontitis, PI classes [0-1]and [1-2]; and GI classes [0-1], [1-2] and [2, 3]; (iii) had a higher PPD (2.02 ± 0.41 vs. 2.35 ± 0.22 mm, respectively), (iv) had lower SBpH (7.59 ± 0.21 vs. 7.45 ± 0.22, respectively) and SFR (1.98 ± 0.28 vs. 1.60 ± 0.32 mL/mn, respectively) and (v) included a higher percentage of participants having a PI class [2, 3] (67.6 vs. 87.9%, respectively). The multivariable regression analysis revealed that only obesity status, age and PI classes influenced the PPD, altogether explained 29.62% of the PPD variance. CONCLUSION: Obesity poses a risk for oral health, and obese adults had altered PPD and lower BSpH and SFR. Dentists should make obese patients aware of the health risks of obesity in an attempt to reduce the potential oral complications associated with this epidemic.

Misspecification of confounder-exposure and confounder-outcome associations leads to bias in effect estimates.

BACKGROUND: Confounding is a common issue in epidemiological research. Commonly used confounder-adjustment methods include multivariable regression analysis and propensity score methods. Although it is common practice to assess the linearity assumption for the exposure-outcome effect, most researchers do not assess linearity of the relationship between the confounder and the exposure and between the confounder and the outcome before adjusting for the confounder in the analysis. Failing to take the true non-linear functional form of the confounder-exposure and confounder-outcome associations into account may result in an under- or overestimation of the true exposure effect. Therefore, this paper aims to demonstrate the importance of assessing the linearity assumption for confounder-exposure and confounder-outcome associations and the importance of correctly specifying these associations when the linearity assumption is violated. METHODS: A Monte Carlo simulation study was used to assess and compare the performance of confounder-adjustment methods when the functional form of the confounder-exposure and confounder-outcome associations were misspecified (i.e., linearity was wrongly assumed) and correctly specified (i.e., linearity was rightly assumed) under multiple sample sizes. An empirical data example was used to illustrate that the misspecification of confounder-exposure and confounder-outcome associations leads to bias. RESULTS: The simulation study illustrated that the exposure effect estimate will be biased when for propensity score (PS) methods the confounder-exposure association is misspecified. For methods in which the outcome is regressed on the confounder or the PS, the exposure effect estimate will be biased if the confounder-outcome association is misspecified. In the empirical data example, correct specification of the confounder-exposure and confounder-outcome associations resulted in smaller exposure effect estimates. CONCLUSION: When attempting to remove bias by adjusting for confounding, misspecification of the confounder-exposure and confounder-outcome associations might actually introduce bias. It is therefore important that researchers not only assess the linearity of the exposure-outcome effect, but also of the confounder-exposure or confounder-outcome associations depending on the confounder-adjustment method used.

Increased complication rates of salvage reverse total shoulder arthroplasty (RTSA) after failed locked plate fixation compared with primary RTSA in the treatment of proximal humeral fractures in elderly patients.

HYPOTHESIS: Common surgical treatment options for proximal humeral fractures in elderly patients include locked plate fixation (LPF) and reverse total shoulder arthroplasty (RTSA). It was hypothesized that secondary RTSA after LPF would be associated with higher complication rates and costs compared with primary RTSA. METHODS: We analyzed the health insurance data of patients aged ≥65 years who received RTSA for the treatment of a proximal humeral fracture between January 2013 and September 2019 with a pre-study phase of 5 years. Multivariable Cox, logistic, and linear regression models were used to evaluate the association between treatment group and complications, hospital length of stay, charges, and mortality rate during a 34-month follow-up period. RESULTS: A total of 14,220 patients underwent primary RTSA and 1282 patients underwent secondary RTSA after prior surgery using LPF for the treatment of proximal humeral fractures. After adjustment for patient characteristics, more surgical complications were observed after secondary RTSA during index hospitalization (odds ratio, 4.62; 95% confidence interval [CI], 4.00-5.34; P < .001) and long-term follow-up (hazard ratio, 1.52; 95% CI, 1.27-1.81; P < .001). Moreover, secondary RTSA was associated with an increased cumulative total cost of €6638.1 (95% CI, €6229.9-€7046.5; P < .001). If conversion from LPF to secondary RTSA occurred during index hospitalization, more major adverse events, more thromboembolic events, and a higher mortality rate were found in the short and long term (all P < .05). CONCLUSION: Secondary RTSA is associated with higher total costs and more complications. Hence, if surgical treatment of a proximal humeral fracture in an elderly patient is needed, prognostic factors for LPF need to be evaluated carefully. If in doubt, the surgeon should opt to perform primary RTSA as patients will benefit in the long term.

Noncollapsibility and its role in quantifying confounding bias in logistic regression.

BACKGROUND: Confounding bias is a common concern in epidemiological research. Its presence is often determined by comparing exposure effects between univariable- and multivariable regression models, using an arbitrary threshold of a 10% difference to indicate confounding bias. However, many clinical researchers are not aware that the use of this change-in-estimate criterion may lead to wrong conclusions when applied to logistic regression coefficients. This is due to a statistical phenomenon called noncollapsibility, which manifests itself in logistic regression models. This paper aims to clarify the role of noncollapsibility in logistic regression and to provide guidance in determining the presence of confounding bias. METHODS: A Monte Carlo simulation study was designed to uncover patterns of confounding bias and noncollapsibility effects in logistic regression. An empirical data example was used to illustrate the inability of the change-in-estimate criterion to distinguish confounding bias from noncollapsibility effects. RESULTS: The simulation study showed that, depending on the sign and magnitude of the confounding bias and the noncollapsibility effect, the difference between the effect estimates from univariable- and multivariable regression models may underestimate or overestimate the magnitude of the confounding bias. Because of the noncollapsibility effect, multivariable regression analysis and inverse probability weighting provided different but valid estimates of the confounder-adjusted exposure effect. In our data example, confounding bias was underestimated by the change in estimate due to the presence of a noncollapsibility effect. CONCLUSION: In logistic regression, the difference between the univariable- and multivariable effect estimate might not only reflect confounding bias but also a noncollapsibility effect. Ideally, the set of confounders is determined at the study design phase and based on subject matter knowledge. To quantify confounding bias, one could compare the unadjusted exposure effect estimate and the estimate from an inverse probability weighted model.

Schistosoma mansoni PCR+ -infected individuals in the Sudan present elevated systemic levels of chemokines when compared to uninfected and egg+ cohorts.

Infections with Schistosoma mansoni remain a major health problem in the Sudan where endemic communities, such as those in Kassala and Khartoum states, continue to face severe social-economic difficulties. Our previous immunoepidemiological findings revealed different immune [cytokine and S. mansoni egg (SEA) antibody] profiles in individuals with active infections (eggs in stool n = 110), individuals positive for S. mansoni via polymerase chain reaction (PCR) using sera (SmPCR+ n = 63) and those uninfected (Sm uninf). As antibody responses to eggs and worms are known to change during infection, we have expanded the profiling further by determining levels of adult worm (SWA) antibodies and nine chemokines in the serum of each individual in the three different cohorts. With the exception of C-C motif chemokine ligand (CCL)2, all measured chemokines were significantly higher in SmPCR+ individuals when compared to the egg+ group and in addition they also presented elevated levels of SWA-specific immunoglobulin (Ig)G2. Multivariable regression analysis further revealed that infection per se was strongly linked to SWA-specific IgG3 levels and CCL5 was strongly associated with a SmPCR+ diagnostic state. In the absence of PCR diagnostics that recognize juvenile worms or schistosomulae motives, identifying schistosome-specific traits should provide better insights into current prevalence rates in endemic communities and, in doing so, take into consideration PCR+ non-egg+ individuals in current treatment programmes.

Multivariable regression analysis of list experiment data on abortion: results from a large, randomly-selected population based study in Liberia.

BACKGROUND: The list experiment is a promising measurement tool for eliciting truthful responses to stigmatized or sensitive health behaviors. However, investigators may be hesitant to adopt the method due to previously untestable assumptions and the perceived inability to conduct multivariable analysis. With a recently developed statistical test that can detect the presence of a design effect - the absence of which is a central assumption of the list experiment method - we sought to test the validity of a list experiment conducted on self-reported abortion in Liberia. We also aim to introduce recently developed multivariable regression estimators for the analysis of list experiment data, to explore relationships between respondent characteristics and having had an abortion - an important component of understanding the experiences of women who have abortions. METHODS: To test the null hypothesis of no design effect in the Liberian list experiment data, we calculated the percentage of each respondent "type," characterized by response to the control items, and compared these percentages across treatment and control groups with a Bonferroni-adjusted alpha criterion. We then implemented two least squares and two maximum likelihood models (four total), each representing different bias-variance trade-offs, to estimate the association between respondent characteristics and abortion. RESULTS: We find no clear evidence of a design effect in list experiment data from Liberia (p = 0.18), affirming the first key assumption of the method. Multivariable analyses suggest a negative association between education and history of abortion. The retrospective nature of measuring lifetime experience of abortion, however, complicates interpretation of results, as the timing and safety of a respondent's abortion may have influenced her ability to pursue an education. CONCLUSION: Our work demonstrates that multivariable analyses, as well as statistical testing of a key design assumption, are possible with list experiment data, although with important limitations when considering lifetime measures. We outline how to implement this methodology with list experiment data in future research.

Survival of Patients with Acute Coronary Syndrome and Hematologic Malignancies-A Real-World Analysis.

BACKGROUND: The impact of the encounter between coronary heart disease (CHD) and cancer, and in particular hematologic malignancies (HM), remains poorly understood. OBJECTIVE: The aim of this analysis was to clarify how HM affects the prognosis of acute coronary syndrome (ACS). We analyzed German health insurance data from 11 regional Ortskrankenkassen (AOK) of patients hospitalized for ACS between January 2010 and December 2018, matched by age, sex and all comorbidities for short- and long-term survival and major adverse cardiac events (MACE). RESULTS: Of 439,716 patients with ACS, 2104 (0.5%) also had an HM. Myelodysplastic/myeloproliferative disorders (27.7%), lymphocytic leukemias (24.8%), and multiple myeloma (22.4%) predominated. These patients were about 6 years older (78 vs. 72 years *). They had an ST-segment elevation myocardial infarction (STEMI, 18.2 vs. 34.9% *) less often and more often had a non-STEMI (NSTEMI, 81.8 vs. 65.1% *). With the exception of dyslipidemia, these patients had more concomitant and previous cardiovascular disease and a worse NYHA stage. They were less likely to undergo coronary angiography (65.3 vs. 71.6% *) and percutaneous coronary intervention (PCI, 44.3 vs. 52.0% *), although the number of bleeding events was not relevantly increased (p = 0.22). After adjustment for the patients' risk profile, the HM was associated with reduced long-term survival. However, this was not true for short-term survival. Here, there was no difference in the STEMI patients, * p < 0.001. CONCLUSION: Survival in ACS and HM is significantly lower, possibly due to the avoidance of PCI because of a perceived increased risk of bleeding.

Modified Fukuda stepping motion assessment of young healthy adults using portable inertial measurement units.

Currently, vestibular rehabilitation approaches used to monitor body position and movement during rehabilitation training require specialized equipment or rely on clinician observation. Thus, a simpler position-sensing approach that can be used to monitor movement during vestibular rehabilitation is required. This study used wearable motion sensors with built-in accelerometers and gyrometers to assess movement in adults. We explored stepping patterns in adults using this motion-sensing system. Six healthy adults (men, age 27.3 ± 5.8 years) underwent a modified Fukuda stepping test (Foulage test [FT]) while wearing a six-axis motion sensor (accelerometer: X-axis, Y-axis, Z-axis; gyrometer: X-axis, Y-axis, Z-axis) positioned at the head, thorax, and lumbar spine. For motion sensor parameters, we calculated the root mean square (RMS), autocorrelation coefficient (AC), power spectrum (PS) of the AC, and Euler angles from the six-axis motion sensor. For the FT parameters, the FT value, step variance, and θ values were calculated. Data were analyzed, and multivariable regression analysis was performed using the FT value, step variance, and θ value as the dependent variables to investigate their influence on dynamic equilibrium. The explanatory variables included the motion sensor parameters, RMS, AC, and PS. Our results suggested that almost no head and lumbar spine movement occurred while stepping with eyes open. Contrastingly, the head and lumbar spine swayed with eyes closed. This accelerometric and gyroscopic device is easy to use, does not require specialized equipment, and can be used to analyze performance in the modified Fukuda stepping test in clinical practice. Inertial sensors have many advantages over other sensing technologies.

Meta-analysis of multi-jurisdictional health administrative data from distributed networks approximated individual-level multivariable regression.

BACKGROUND AND OBJECTIVES: Compare meta-analysis in a distributed network to individual-level analysis for assessment of time trends of health services utilization with health administrative data. METHODS: We used administrative data from Ontario, Canada to analyze temporal trends in pediatric inflammatory bowel disease health services use. Beta coefficients were obtained using negative binomial, logistic, and Cox proportional hazards regression models. We replicated the individual-level analyses in each Ontario Local Health Integration Network (LHIN), then meta-analyzed aggregate trends using both fixed and random effects meta-analysis. We compared the pooled estimates of effect with individual-level analysis. RESULTS: Beta coefficients, summary effect estimates, and 95% confidence intervals (CIs) from the meta-analysis of data from distributed networks were not different than those from individual-level data, regardless of meta-analytic approach used. For example, the 5-year odds ratio of colectomy in ulcerative colitis using individual-level analysis was 0.978 (95% CI 0.950 to 1.007) compared to distributed network fixed effects meta-analysis: 0.982 (95% CI 0.950 to 1.015), and random effects meta-analysis: 0.982 (95% CI 0.950 to 1.015). CONCLUSION: Meta-analysis of multi-jurisdictional estimates were similar to estimates obtained from individual-level analysis. This method is a valid alternative for analysis of multi-jurisdictional data when individual-level data cannot be shared.

Patient factors related to early implant failures in the edentulous jaw: A large retrospective case-control study.

BACKGROUND: Dental implants provide anchorage for dental prostheses to restore functions for individuals with edentulous jaws. During the healing phase, proper osseointegration is required to prevent early implant failure. More knowledge is needed regarding factors related to early failure of dental implants. PURPOSE: The aim of the present study was to identify possible risk factors for early implant failure, with respect to anamnestic and clinical parameters. MATERIALS AND METHODS: All patients with edentulous jaws with early implant failure (n = 408) from one referral clinic were compared with a matched control group (n = 408) with no implant failure. Early implant failure was identified during the first year of prosthetic function. Matching was performed on age, gender, year of surgery, type of jaw, and type of implant surface. In addition, data on anamnestic and clinical parameters were collected. The data were analyzed with a multivariable logistic regression model using early implant failure as the binary outcome. RESULTS: Five anamnestic factors were statistically significant with respect to higher probability for early implant failure: systemic disease, allergies in general, food allergies, smoking, and intake of analgesic medication. Four clinical conditions (i.e., implants in the opposing jaw, low primary stability, reduced bone volume, and healing complications) were also related to higher probability for early implant failure. CONCLUSIONS: This study identified nine factors associated with early implant failure, several related to patient's general health. Further investigations are needed to fully understand the causality between the obtained variables and early implant failure.

Distinct Schistosoma mansoni-Specific Immunoglobulin Subclasses Are Induced by Different Schistosoma mansoni Stages-A Tool to Decipher Schistosoma mansoni Infection Stages.

Despite the existence of an effective medication against schistosomiasis, the disease remains a major health problem in affected areas, especially for those lacking appropriate sanitary facilities. Moreover, treatment cannot prevent re-infection since it is only effective on adult schistosome worms. Previous retrospective studies in the Sudan have discovered unique immuno-epidemiological profiles in uninfected individuals and those positive for Schistosoma mansoni via polymerase chain reaction (PCR) but egg-negative and those with eggs in their stool. Expanding on these data, serum samples from these individuals were further investigated for the presence of cercarial (SmCTF)-specific antibodies, which would indicate immune responses at the early stages of infection. Indeed, SmCTF IgG1, 2, 3 and 4 levels were significantly elevated in SmPCR+ individuals when compared to egg+ patients. Following multivariable regression analysis, including SmCTF-specific Igs, Schistosoma egg antigen (SEA)-specific and Schistosoma worm antigen (SWA)-specific immunoglobulins revealed a specific immunoglobulin (Ig) profile of individuals presenting different states of infection, which may be a useful future tool in order to identify egg- individuals and thereby prevent unnecessary treatments.

Associations of health services utilization by prescription drug coverage and immigration category in Ontario, Canada.

Canada is the only high-income country with a universal healthcare system that does not provide prescription drug coverage for all its residents. This study examines whether Canadians' prescription drug coverage status is associated with their health services use and how this association differs by gender across non-migrants and three categories of migrants: economic immigrants, family-class immigrants, and refugees. Very few studies have examined differences across these migrant groups, and there is a need to do so as they experience varying health disparities. This study contributes to the prescription drug coverage, migration and health literature by employing an intersectional lens to analyze a sample of Ontario working-aged residents (n=39,792) generated from linking the Canadian Community Health Survey (2005, 2008, 2013, 2014) and Longitudinal Immigrant Database. Predicted probabilities and average marginal effects from multivariable logistic regression models were generated, and interaction effects between prescription drug coverage and immigrant status were examined. The study reveals important differences in the use of health services across prescription drug coverage groups by immigration status. As the general debate about universal pharmacare in Canada is ongoing, this study reveals that drug insurance is positively associated with health services use of most migrants and non-migrants, however, some immigrant women may still experience barriers to access general practitioner services. If pharmacare is introduced, ongoing evaluation is needed to ensure that its implementation produces equitable outcomes for all.