On Odds Ratios Research Articles

Synergistic effect of pain and deficits in ADL towards general practitioner visits.

Pain and activities of daily living (ADLs) deficits are common problems among elderly people who visit general practitioners (GPs). To examine whether the probability of visiting a GP is related to deficits in ADLs and pain, and whether these factors act synergistically towards GP visits. A total of 3097 subjects aged ≥65 years from the Austrian Health Interview Survey formed the cohort. Visiting the GP in the last 4 weeks, chronic pain (CP; pain for at least 3 months) and deficits in ADLs across 11 dimensions were reported. Binary logistic regression models were applied and were stepwise controlled for possible confounders. Based on odds ratios (OR), the synergy index (SI), population attributable fraction (PAF) and relative excess risk due to interaction (RERI) were calculated. Overall, 61.0% visited their GP; 51.2% were affected by ADL deficits and 42.2% by CP. In subjects with ADL deficits, the OR for GP consultation was 1.32 (95% confidence interval [CI] 1.11-1.56) and in subjects with CP, 1.93 (95% CI 1.63-2.27) in the fully adjusted model. The OR for those affected by both was 2.56 (95% CI 2.08-3.15); SI was 1.82 (95% CI 1.04-3.18), PAF was 0.27 (95% CI 0.08-0.47) and RERI was 0.70 (95% CI 0.13-1.27). There is a strong synergistic effect of CP and deficits in ADL in patients ≥65 years on visiting the GP. Prevention, screening, treatment and rehabilitation in this population should focus on both CP and ADL deficits.

Electronic medical record data to identify variables associated with a fibromyalgia diagnosis: importance of health care resource utilization.

BackgroundDiagnosis of fibromyalgia (FM) is often challenging. Identifying factors associated with an FM diagnosis may guide health care providers in implementing appropriate diagnostic and management strategies.MethodsThis retrospective study used the de-identified Humedica electronic medical record (EMR) database to identify variables associated with an FM diagnosis. Cases (n=4,296) were subjects ≥18 years old with ≥2 International Classification of Diseases, Ninth Revision (ICD-9) codes for FM (729.1) ≥30 days apart during 2012, associated with an integrated delivery network, with ≥1 encounter with a health care provider in 2011 and 2012. Controls without FM (no-FM; n=583,665) did not have the ICD-9 codes for FM. Demographic, clinical, and health care resource utilization variables were extracted from structured EMR data. Univariate analysis identified variables showing significant differences between the cohorts based on odds ratios (ORs).ResultsConsistent with FM epidemiology, FM subjects were predominantly female (78.7% vs 64.5%; P<0.0001) and slightly older (mean age 53.3 vs 52.7 years; P=0.0318). Relative to the no-FM cohort, the FM cohort was characterized by a higher prevalence of nearly all evaluated comorbidities; the ORs suggested a higher likelihood of an FM diagnosis (P<0.0001), especially for musculoskeletal and neuropathic pain conditions (OR 3.1 for each condition). Variables potentially associated with an FM diagnosis included higher levels of use of specific health care resources including emergency-room visits, outpatient visits, hospitalizations, and medications. Units used per subject for emergency-room visits, outpatient visits, hospitalizations, and medications were also significantly higher in the FM cohort (P<0.0001), confirming resource utilization as an important variable associated with an FM diagnosis.ConclusionSignificant differences between the FM and no-FM cohorts were observed for nearly all the demographic, clinical, and health care resource variables, suggesting an association with FM diagnosis. These results also support use of EMR data for identifying variables associated with FM, which may help in the diagnosis and management of this condition.

Preoperative risk factors for anastomotic leakage after resection for colorectal cancer: a systematic review and meta‐analysis

Colorectal anastomotic leakage is a serious complication. Despite extensive research, no consensus on the most important preoperative risk factors exists. The aim of this systematic review and meta-analysis was to evaluate risk factors for anastomotic leakage in patients operated with colorectal resection. The databases MEDLINE, Embase and CINAHL were searched for prospective observational studies on preoperative risk factors for anastomotic leakage. Meta-analyses were performed on outcomes based on odds ratios (OR) from multivariate regression analyses. The Newcastle-Ottawa scale was used for bias assessment within studies, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used for quality assessment of evidence on outcome levels. This review included 23 studies evaluating 110,272 patients undergoing colorectal resection for cancer. The meta-analyses found that a low rectal anastomosis [OR = 3.26 (95% CI: 2.31-4.62)], male gender [OR = 1.48 (95% CI: 1.37-1.60)] and preoperative radiotherapy [OR = 1.65 (95% CI: 1.06-2.56)] may be risk factors for anastomotic leakage. Primarily as a result of observational design, the quality of evidence was regarded as moderate or low for these risk factors according to the GRADE approach. Based on the best available evidence, important preoperative risk factors for colorectal anastomotic leakage have been identified. Knowledge on risk factors may influence treatment and procedure-related decisions, and possibly reduce the leakage rate.

Improved Apnea-Hypopnea Index and Lowest Oxygen Saturation After Maxillomandibular Advancement With or Without Counterclockwise Rotation in Patients With Obstructive Sleep Apnea: A Meta-Analysis

This study investigated whether patients with obstructive sleep apnea (OSA) who undergo maxillomandibular advancement (MMA) with counterclockwise (CCW) rotation compared with those who undergo MMA without CCW rotation have better outcomes. This was a systematic review with meta-analysis. The Medline and Cochrane databaseswere searched for randomized controlled trials using Medical Subject Headings. The predictor variable was operative technique, namely MMA with or without CCW rotation of the maxillofacial complex. The key outcome variables were changes in pre- and postsurgical values of pharyngeal volume measured on computed tomogram or cone-beam computed tomogram and changes in Apnea-Hypopnea Index (AHI) and lowest oxygen saturation (LSAT) values after surgery. Data were subjected to a meta-analysis based on odds ratios (OR) with 95% confidence intervals (CIs) and P values lower than .05 by χ(2) test were considered significant. Twenty-one randomized controlled trials were identified and 4 were assessed for the variables of interest. Postoperative AHI and LSAT measurements showed vast improvement. The sample was not large enough to make a correlation between pharyngeal volume changes and surgical method used. Postoperative parameters included an AHI lower than 5 (OR= 14.9; 95% CI, 2.7-83.5; P= .002), an AHI lower than 20 (OR = 114.8; 95% CI, 23.5-561.1; P <.00001), pooled results of a 50% decrease in the AHI (OR= 6.1; 95% CI, 2.2-17.0; P= .0006), and an increase greater than 90% in LSAT measurements during sleep (OR= 6.0; 95% CI, 1.8-19.9; P= .003). The funnel plot showed no evidence of publication bias. CCW-MMA or MMA in patients with OSA results in a statistically meaningful decrease in postoperative AHI and a statistically meaningful increase in postoperative LSAT.

Differential Factors of Contraceptive Use and Adverse Outcomes of Pregnancy in Women with Ages 15 to 49 in Pretoria, South Africa

Challenges of teenage pregnancy and adverse outcomes of pregnancy constitute a major public health problem in South African women of the childbearing age of 15 to 49 years. This is a 6-year long study that was conducted in Pretoria, South Africa in order to identify factors that affect utilization of modern contraceptives and adverse pregnancy outcomes in women of the childbearing age of 15 to 49 years. Data analysis was conducted by using two-by-two Pearson’s chisquare tests of associations, binary logistic regression analysis, survival analysis, and multilevel analysis. The study showed that the percentage of women who regularly used modern family planning methods such as condoms, pills, injections, intra-uterine devices and sterilization was 41.74%. The average ages of women at first sex and pregnancy were 18.72 and 19.36 years respectively. Adverse outcomes of pregnancy occurred in 12.19% of women. Based on Odds Ratios (OR) estimated from binary logistic regression analysis, utilization of contraceptives was significantly influenced by easy access to family planning services, level of support from sexual partner, and young age at first pregnancy. Based on Hazard Ratios (HR) estimated from the Cox Proportional Hazards Model, the occurrence of adverse outcomes of pregnancy was significantly influenced by easy access to family planning services, unwanted pregnancy, and young age at first pregnancy. Women who experienced adverse outcomes of pregnancy were characterized by poor utilization of reproductive health and modern family planning services. There was a significant difference among the 20 health service delivery wards and 11 health service facilities in which reproductive health services were delivered to women with regards to the quality of service delivery.

The Risk of Congenital Malformations Associated With Exposure to β-Blockers Early in Pregnancy

β-blockers are commonly used during the first trimester of pregnancy. Data about risks of congenital anomalies in offspring have not been summarized. We performed a meta-analysis to determine teratogenicity of β-blockers in early pregnancy. A systematic literature search was performed using PubMed, EMBASE, Cochrane Clinical Trials, and hand search. Meta-analyses were performed using random-effects models based on odds ratios (ORs). Prespecified subgroup analyses were performed to explore heterogeneity. Randomized controlled trials or observational studies examining risks of congenital malformations associated with first trimester β-blocker exposure compared with no exposure were included. Thirteen population-based case–control or cohort studies were identified. Based on meta-analyses, first-trimester oral β-blocker use showed no increased odds of all or major congenital anomalies (OR=1.00; 95% confidence interval, 0.91–1.10; 5 studies). However, in analyses examining organ-specific malformations, increased odds of cardiovascular defects (OR=2.01; 95% confidence interval, 1.18–3.42; 4 studies), cleft lip/palate (OR=3.11; 95% confidence interval, 1.79–5.43; 2 studies), and neural tube defects (OR=3.56; 95% confidence interval, 1.19–10.67; 2 studies) were observed. The effects on severe hypospadias were nonsignificant (1 study). Causality is difficult to interpret given the small number of heterogeneous studies and possibility of biases. Given the frequency of this exposure in pregnancy, further research is needed.

The Impact of Underutilization of Modern Family Planning Methods on Adverse Outcomes of Pregnancy in Women Aged 15 to 49 in Pretoria, South Africa

This paper is a result of a 6-year long follow-up study that was conducted in Pretoria, South Africa between 2004 and 2009 in order to assess the impact of underutilization of modern family planning methods on adverse outcomes of pregnancy in women of the childbearing age of 15–49 years. The Cox Proportional Hazards Model was used for estimating hazard ratios. Multilevel analysis was used for estimating variability in the utilization of modern family planning methods at service delivery wards and health service facilities. The study showed that women who experienced adverse outcomes of pregnancy were characterized by poor utilization of reproductive health and modern family planning services. The percentage of women who regularly used modern family planning methods such as condoms, pills, injections, intra-uterine devices and sterilization was 41.74%. The average ages of women at first sex and pregnancy were 18.72 and 19.36 years, respectively. Adverse outcomes of pregnancy occurred in 12.19% of women. Based on odds ratios (ORs) estimated from binary logistic regression analysis, utilization of contraceptives was significantly influenced by the degree of access to family planning services, level of support from sexual partner, and young age at first pregnancy. The occurrence of adverse outcomes of pregnancy was significantly influenced by easy access to family planning services, unwanted pregnancy, and young age at first pregnancy. There was a significant difference among the 20 health service delivery wards and 11 health service facilities in which reproductive health services were delivered to women with regards to the quality of service delivery.

Significant differences in pediatric psychotropic side effects: Implications for school performance.

Some side effects (SEs) of increasingly prescribed psychotropic medications can impact student performance in school. SE risk varies, even among drugs from the same class (e.g., antidepressants). Knowing which SEs occur significantly more often than others may enable school psychologists to enhance collaborative risk-benefit analysis, medication monitoring, data-based decision-making, and inform mitigation efforts. SE data from Full Prescribing Information (PI) on the FDA website for ADHD drugs, atypical antipsychotics, and antidepressants with pediatric indications were analyzed. Risk ratios (RR) are reported for each drug within a category compared with placebo. RR tables and graphs inform the reader about SE incidence differences for each drug and provide clear evidence of the wide variability in SE incidence in the FDA data. Breslow-Day and Cochran Mantel-Haenszel methods were used to test for drug-placebo SE differences and to test for significance across drugs within each category based on odds ratios (ORs). Significant drug-placebo differences were found for each drug compared with placebo, when odds were pooled across all drugs in a category compared with placebo, and between some drugs within categories. Unexpectedly, many large RR differences did not reach significance. Potential explanations are offered, including limitations of the FDA data sets and statistical and methodological issues. Future research directions are offered. The potential impact of certain SEs on school performance, mitigation strategies, and the potential role of the school psychologist is discussed, with consideration for ethical and legal limitations.

Different interaction concepts to detect gene-environment interactions in the context of upper aero-digestive tract cancer

Introduction: Tobacco smoking and consumption of alcoholic beverages are established causes of cancers of the upper aero-digestive tract (UADT) and reduced intake of vegetables and fruits are likely causes. Little is known, however, about the role of gene-environment interactions (GEIs) respecting nutritional factors. Material and Methods: The study is embedded in the Alcohol-Related Cancers and Genetic Susceptibility in Europe (ARCAGE) study, a multi-centre case-control study conducted 2002–2005 in 10 European countries (Lagiou, 2009). Dietary habits were assessed using a semi-quantitative food frequency questionnaire. The analysis dataset included 1,395 controls and 1,379 cases. We used approximately 50% of the data for an exploratory screening procedure to generate a list of several potential gene-nutrition interactions. The remaining 50% build an independent dataset, which is used to estimate interaction effects between genes and nutrition variables. Logistic regression models are applied to estimate various interaction effects that are based on odds ratios (OR) like RERI (relative excess risk due to interaction), AP (attributable proportion due to interaction), the synergy index (S) and the multiplicative synergy index (SM). Interaction measures of combined gene-nutrition information will be compared with interaction effects of stratified data. Results: We observe inverse interaction effects between fruit consumption and MTHFR (folate metabolism). Homozygous minor allele carriers (AA genotype) show a significantly increased OR with less than daily fruit consumption (OR=3.8, CI=2.2–3.8) compared to non-carriers with more than daily fruit consumption. RERI=1.99 (CI=-0.1–4.0) indicates that the excess risk due to the exposure combination of the AA-genotype and „daily fruit consumption“ is 1.99 times higher compared to participants being exposed to neither of these two factors. The synergy index shows a significant synergistic departure from additivity (S=3.3, CI=1.2–8.9). Discussion: We demonstrate that different interaction measures lead to different interpretations of „interaction“. This will be discussed in the context of GEIs that could modify the risk of UADT cancers.

Impact of random and systematic recall errors and selection bias in case-control studies on mobile phone use and brain tumors in adolescents (CEFALO study)

Whether the use of mobile phones is a risk factor for brain tumors in adolescents is currently being studied. Case--control studies investigating this possible relationship are prone to recall error and selection bias. We assessed the potential impact of random and systematic recall error and selection bias on odds ratios (ORs) by performing simulations based on real data from an ongoing case--control study of mobile phones and brain tumor risk in children and adolescents (CEFALO study). Simulations were conducted for two mobile phone exposure categories: regular and heavy use. Our choice of levels of recall error was guided by a validation study that compared objective network operator data with the self-reported amount of mobile phone use in CEFALO. In our validation study, cases overestimated their number of calls by 9% on average and controls by 34%. Cases also overestimated their duration of calls by 52% on average and controls by 163%. The participation rates in CEFALO were 83% for cases and 71% for controls. In a variety of scenarios, the combined impact of recall error and selection bias on the estimated ORs was complex. These simulations are useful for the interpretation of previous case-control studies on brain tumor and mobile phone use in adults as well as for the interpretation of future studies on adolescents.

Do low control response rates always affect the findings? Assessments of smoking and obesity in two Australian case‐control studies of cancer

Participation rates have been declining in case-control studies, particularly among controls, raising concerns about possible bias. Formal assessments of the effect of low participation on odds ratios (OR) are seldom presented however. We sought to quantify possible bias using multiple imputation techniques. Using data from two Australian case-control studies, we estimated the relative risks of oesophageal squamous cell carcinoma (OSCC) and adenocarcinoma (OAC), and serous ovarian cancer (SOC) associated with smoking and body mass index (BMI). We compared ORs observed using self-reported data from participating controls with ORs derived using imputed exposures for non-participating controls. Participating controls were less likely than non-participants to smoke currently. Smoking remained significantly associated with oesophageal cancer even under the most extreme assumption of smoking prevalence among non-participants (OSCC: observed OR 6.54, 4.62-9.28, imputed OR 3.94, 2.83-5.49; OAC: observed OR 2.69, 1.87-3.85 imputed OR 1.58, 1.13-2.22). For SOC however, risks associated with smoking were attenuated to null under plausible smoking assumptions among non-participants. BMI distributions were similar among participating and non-participating controls, and risk estimates were essentially unchanged. Bias is not an inevitable consequence of low control participation and depends on the association examined. Sensitivity analyses can assist in interpretation of results.

Study on the relationship between body mass index and health-related quality of life in middle-aged or older Chinese adults

To study the association between body mass index (BMI) and the health-related quality of life (HRQOL) in the middle-aged and older Chinese people. Data of 9539 middle-aged and older adults was collected from a cross-sectional survey performed in 9 provinces of China (Jiangsu, Anhui, Gansu, Qinghai, Fujian, Beijing, Jilin, Jiangxi and Henan province). MOS SF-36 was used to measure HRQOL. BMI classification was in accordance with the criteria recommended by the Ministry of Health of China. Rank sum test was used to compare HRQOL between subjects with normal weight and those with different BMI classification. Multiple logistic regression analysis was used to assess the association of HRQOL with BMI after adjusted for sex, age, marital, education, physical activity status and chronic diseases. When compared with middle-aged and older adults at normal weight range (18.5< or =BMI<24), data on physical domain (P<0.001), mental domain (P< 0.01) and 8 dimensions of HRQOL (physical functioning, mental health, P<0.05; role-physical, bodily pain, general health, vitality, social functioning, role-emotional, P<0.01) among subjects with underweight (BMI<18.5) were significantly lower while mental component summary (P<0.05) of overweight subjects (24< or =BMI<28) was significantly higher. Obese subjects (BMI> or =28) had worse physical function (physical functioning, P<0.01) but better mental health (mental health, P<0.01; mental component summary, P<0.05). After adjusting for other factors, and compared to middle aged and older adults with normal weight, data on odds ratios (ORs) of impaired HRQOL in physical domain (OR=1.67, 95% CI: 1.35-2.06), mental domain (OR=1.39, 95% CI: 1.13-1.70) and 8 dimensions increased among underweight subjects while ORs of impaired HRQOL in mental domain (OR=0.86, 95% CI: 0.78-0.95) and role-physical, vitality, social functioning, role-emotional and mental health dimensions decreased among overweight subjects. ORs increased (OR= 1.51, 95% CI: 1.27-1.80) in impaired HRQOL in physical functioning dimension but decreased in mental domain (OR=0.71, 95% CI: 0.60-0.85) as well as vitality, role-emotional and mental health dimensions among obese subjects. HRQOL of each domain were different among middle aged and older adults with different BMI classification. Underweight people had poor HRQOL in both physical domain and psychological domain, and obese people had poor physical function but good mental health condition.

Low birthweight in relation to placental abruption and maternal thrombophilia status

The objective of the study was to evaluate whether the association between low birthweight and placental abruption is mediated through preterm birth or restricted fetal growth and whether these associations were influenced by maternal thrombophilia status. Data were derived from the New Jersey-Placental Abruption Study, an ongoing, multicenter, case-control study conducted in New Jersey since August 2002. Abruption cases (n = 156) were identified based on a clinical diagnosis, and controls (n = 170) were matched to cases based on parity and maternal race. Low birthweight (<2500 g) was stratified based on preterm birth (<37 weeks' gestation) and small for gestational age (birthweight < the 10th percentile for gestational age). Maternal thrombophilia assessment was based on serum evaluation (protein C and S deficiency, activated protein C resistance ratio, and anticardiolipin antibodies) as well as genetic polymorphisms (methylenetetrahydrofolate reductase, prothrombin gene, and factor V Leiden). Associations were expressed based on odds ratios (ORs) with 95% confidence interval (CI). Among abruption cases, 60.3% (n = 94) were low birthweight in comparison with 11.2% (n = 19) of controls (OR, 13.7; 95% CI, 7.4-25.2). Furthermore, placental abruption had a significantly increased association with preterm birth in both small for gestational age (OR, 17.4; 95% CI, 4.6-64.9) and appropriately grown fetuses (OR, 15.8; 95% CI, 8.4-29.8). However, the association between abruption and low birthweight were similar between women with and without thrombophilia. The association between placental abruption and low birthweight is chiefly mediated through preterm birth, and this association does not appear to be modified by maternal thrombophilia status.

Family history of coronary heart disease is associated with a higher incidence of nonalcoholic fatty liver disease: Central obesity the likely link

To examine the relationship between family history of coronary heart disease (CHD), hypertension, and diabetes with risk of non-alcoholic fatty liver disease (NAFLD), and the possible interaction between these family histories and metabolic components for NAFLD. The 202 health office workers with no evidence of excessive alcohol drinking or hepatitis B or C virus infection were enrolled in the present study performed from March to June 2004. NAFLD was identified in 68 subjects by abdominal ultrasound. Logistic regression analysis showed that the presence of CHD family history increased the risk of NAFLD by 2.25-fold, 95% CI 1.1-4.1 (P = 0.014), while family history of diabetes or hypertension did not increase the risk. In combination with the presence of a family history of CHD, the effect on odds ratios (ORs) was increased for several metabolic features in predicting the incidence of NAFLD, including increased waist circumference, hypertriglyceridemia, hypertension and the occurrence of the metabolic syndrome. In a logistic regression model, the CHD family history enhances the summary predictive power of baseline clinical variables for NAFLD, but when the occurrence of increased waist circumference and hypertriglyceridemia are considered, the predictive value of a family history of CHD is no longer significant. This study has shown that the CHD family history may be clinically useful and associated with the occurrence of NAFLD, and that the likely link is through central obesity and the metabolic syndrome.

Simple methods for checking for possible errors in reported odds ratios, relative risks and confidence intervals

Meta-analyses of data from epidemiological studies are often based on odds ratios (ORs) or relative risks (RRs) and their 95 per cent confidence intervals (CIs) as reported by the authors. Where possible ORs, RRs and CIs should be checked against the source data. Some simple methods are presented for checking the validity of reported ORs, RRs and CIs where the source data are not available. These methods include inferring the minimum total number of subjects in the study, the minimum total number of cases and the minimum number there must be in any disease/exposure category. Examples taken from the literature on environmental tobacco smoke exposure (ETS) illustrate that errors in published data are not infrequent and may stay undetected in meta-analyses.