Global incidence of caesarean deliveries on maternal request: a systematic review and meta-regression.

BACKGROUND: Caesarean delivery on maternal request (CDMR) is considered a significant contributor to the unprecedented increase in caesarean deliveries (CDs) for nonclinical reasons. Current literature lacks a reliable assessment of the rate of CDMR, which hinders the planning and delivery of appropriate interventions for reducing CDMR rates. OBJECTIVES: To conduct a systematic review of the literature and meta-regression to explore the global incidence of CDMR. SEARCH STRATEGY: PubMed, Embase, CINAHL, Medline, Google scholar and grey literature were searched from January 1985 to May 2019. SELECTION CRITERIA: Observational studies that report CDMR data were included. We excluded non-English articles, case notes, editorial reviews and articles reporting elective CDs from pregnancy risk factors. DATA COLLECTION AND ANALYSIS: Two reviewers independently conducted the screening and quality appraisal using a validated tool. The weighted average of CDMR over total deliveries (absolute proportion) and by total CDs (relative proportion) were generated. Quality-effects meta-regression was used to explain the variability of the CDMR estimates by moderators, including study methodology and demography of study participants. MAIN RESULTS: We identified 31 articles from 14 countries that include 5 million total births. The absolute proportion of CDMR varies between 0.2 and 42.0%, with significant variations across studies and subgroups. The economic status of the country and study year together explained 84% of the absolute and 76% of the relative proportion of CDMR variation. CONCLUSIONS: An appropriate reporting of CDMR should be a key priority in maternal health policies and practices. TWEETABLE ABSTRACT: Globally, the proportion of maternal requested caesarean delivery has mostly been influenced by the economic status of the country.

The risk of developing major depression among individuals with subthreshold depression: a systematic review and meta-analysis of longitudinal cohort studies.

BACKGROUND: Studies have consistently shown that subthreshold depression is associated with an increased risk of developing major depression. However, no study has yet calculated a pooled estimate that quantifies the magnitude of this risk across multiple studies. METHODS: We conducted a systematic review to identify longitudinal cohort studies containing data on the association between subthreshold depression and future major depression. A baseline meta-analysis was conducted using the inverse variance heterogeneity method to calculate the incidence rate ratio (IRR) of major depression among people with subthreshold depression relative to non-depressed controls. Subgroup analyses were conducted to investigate whether IRR estimates differed between studies categorised by age group or sample type. Sensitivity analyses were also conducted to test the robustness of baseline results to several sources of study heterogeneity, such as the case definition for subthreshold depression. RESULTS: Data from 16 studies (n = 67 318) revealed that people with subthreshold depression had an increased risk of developing major depression (IRR = 1.95, 95% confidence interval 1.28-2.97). Subgroup analyses estimated similar IRRs for different age groups (youth, adults and the elderly) and sample types (community-based and primary care). Sensitivity analyses demonstrated that baseline results were robust to different sources of study heterogeneity. CONCLUSION: The results of this study support the scaling up of effective indicated prevention interventions for people with subthreshold depression, regardless of age group or setting.

Hospital effect on infections after four major surgical procedures: outlier and volume-outcome analysis using all-inclusive state data.

BACKGROUND: Hospital volume is known to have a direct impact on the outcomes of major surgical procedures. However, it is unclear if the evidence applies specifically to surgical site infections. AIMS: To determine if there are procedure-specific hospital outliers [with higher surgical site infection rates (SSIRs)] for four major surgical procedures, and to examine if hospital volume is associated with SSIRs in the context of outlier performance in New South Wales (NSW), Australia. METHODS: Adults who underwent one of four surgical procedures (colorectal, joint replacement, spinal and cardiac procedures) at a NSW healthcare facility between 2002 and 2013 were included. The hospital volume for each of the four surgical procedures was categorized into tertiles (low, medium and high). Multi-variable logistic regression models were built to estimate the expected SSIR for each procedure. The expected SSIRs were used to compute indirect standardized SSIRs which were then plotted in funnel plots to identify hospital outliers. FINDINGS: One hospital was identified to be an overall outlier (higher SSIRs for three of the four procedures performed in its facilities), whereas two hospitals were outliers for one specific procedure throughout the entire study period. Low-volume facilities performed the best for colorectal surgery and worst for joint replacement and cardiac surgery. One high-volume facility was an outlier for spinal surgery. CONCLUSIONS: Surgical site infections seem to be mainly a procedure-specific, as opposed to a hospital-specific, phenomenon in NSW. The association between hospital volume and SSIRs differs for different surgical procedures.

Total temporomandibular joint replacement prostheses: a systematic review and bias-adjusted meta-analysis.

The aim of the present study was to determine which prosthesis has resulted in the best outcomes after total temporomandibular joint replacement (TMJR). A comprehensive electronic search was undertaken in September 2015. Inclusion criteria encompassed studies that described one of the three current TMJR systems and that had pre- and postoperative data on at least two of the following TMJR indications: pain, diet, function, and maximum inter-incisal opening (MIO). Sixteen papers were included in the systematic review, reporting 10 retrospective studies and six prospective studies (no randomized controlled or case-controlled trials). A total 312 patients with 505 TMJ Concepts prostheses, 728 patients with 1048 Biomet prostheses, and 125 patients with 196 Nexus prostheses were included in the analysis. There was no real difference between the various TMJR systems in terms of pain or diet scores. Function scores improved with the TMJ Concepts, but this was the only prosthesis for which data were available. Biomet prostheses appeared to have a greater increase in MIO mean gain compared to TMJ Concepts and Nexus prostheses; however this was heavily biased by one study. Without this study, there was no real difference in MIO. It is concluded that the prostheses are similar, but most data are available for the TMJ Concepts prosthesis, with results being favourable.

An Improved Classification of Kidney Function Recovery Using Estimated Glomerular Filtration Rate Slope Post-transplantation.

BACKGROUND: The impact of renal function recovery on graft survival was examined using estimated glomerular filtration rate (eGFR) slope after kidney transplantation (GAP classification); this was compared to the conventional classification of immediate graft function (IGF), slow graft function (SGF), and delayed graft function (DGF). MATERIALS AND METHODS: Overall, 541 cases of cadaveric renal transplants were reviewed from a prospective transplant database. eGFR and its slope were measured using the harmonic mean over the first week post-transplantation. Next, 495 kidney transplant recipients from an independent institution were assessed to determine the prognostic value of graft function based on the eGFR slope. RESULTS: The main discrimination of eGFR slopes occurred within the first 7 days. Three groups in the GAP classification (Good graft function, Average graft function, Poor graft function) were defined based on eGFR slope tertiles: good graft function (GGF), average graft function (AGF), and poor graft function (PGF) were defined based on the ΔCrCL per day over the first 7 days: <1 mL/min, 1-4 mL/min, and >4 mL/min, respectively. When applied to the validation cohort, the 5-year graft failure was 20% for the PGF group, 4% for the AGF group, and 3% for the GGF group. Multivariable Cox regression analysis demonstrated better prediction of long-term graft function with the new classification (C statistic 0.49 [old)] vs 0.61 [new]). CONCLUSION: The new GAP criteria were better at predicting long-term graft survival and renal function compared to the conventional classification system, and deserve further consideration in future studies.

Sleep quality and obesity in young subjects: a meta-analysis.

OBJECTIVES: To assess the effect of poor sleep quality on Overweight/Obesity (Ow/Ob) in young subjects, and explore if this association is independent of sleep duration. METHODS: Pubmed, EMBASE, and MEDLINE databases were searched for papers on sleep quality and overweight/obesity, focusing on children, adolescents, and young adults. Studies based on subjects with medical/psychological problems or published in languages other than English were excluded. Quality effects model was used to pool studies for meta-analysis. RESULTS: Findings from the systematic review suggest a link between poor sleep quality and Ow/Ob in young subjects. Pooled estimate (from 26,553 subjects) suggest a role of inadequate sleep (including both short duration and poor quality) in Ow/Ob (OR: 1.27 95% CI: 1.05-1.53). Sub-group-analyses suggest considerably higher odds of Ow/Ob (OR = 1.46, 95% CI: 1.24-1.72) in young subjects with poor sleep quality (independent of duration). CONCLUSIONS: Poor sleep quality seems to be associated with Ow/Ob, and some studies indicate this association to be independent of duration. Therefore, considering only sleep duration might not help in disentangling sleep-obesity association. However, this review is mostly composed of cross-sectional studies. Therefore, a causal link or the stability of the sleep quality and Ow/Ob association could not be established.

The global burden of major infectious complications following prostate biopsy.

We present a systematic review providing estimates of the overall and regional burden of infectious complications following prostate biopsy. A directly standardized prevalence estimate was used because it reflects the burden of disease more explicitly. Complications included sepsis, hospitalization, bacteraemia, bacteriuria, and acute urinary retention after biopsy. There were 165 articles, comprising 162 577 patients, included in the final analysis. Our findings demonstrate that transrectal biopsy was associated with a higher burden of hospitalization (1·1% vs. 0·9%) and sepsis (0·8% vs. 0·1%) compared to transperineal biopsy, while acute urinary retention was more prevalent after transperineal than transrectal biopsy (4·2% vs. 0·9%). The differences were statistically non-significant because of large heterogeneity across countries. We also demonstrate and discuss regional variations in complication rates, with Asian studies reporting higher rates of sepsis and hospitalization.

Caesarean delivery and the risk of offspring overweight and obesity over the life course: a systematic review and bias-adjusted meta-analysis.

A causal role of Caesarean delivery (CD) on developing overweight and obesity in the life course of offspring has been postulated. However, the true strength of this association is not clear and the potential for confounding has not been adequately addressed. A systematic review and meta-analysis were conducted to evaluate the strength of this association, this time using a bias-adjusted model in addition to conventional methods. Our search yielded 32 estimates from 14 publications (n = 261,000) for meta-analysis. The pooled analysis of seven estimates (n = 194,463) demonstrated a trend only towards a risk increase (RR = 1.15; 95% CI:0.94, 1.40) in overweight and obesity combined (ow+ob) due to CD in early childhood (0-5 years) and a similar trend was observed for mid-childhood and adolescence (5-18 years). In adulthood, a moderate increase in risk for ow+ob due to CD was observed (n = 30,200) (RR = 1.28; 95% CI 1.02, 1.34). Results for obesity and overweight separately were stronger for obesity and demonstrated a decreasing effect across the three life stages. Conventional methods of analysis suggested less uncertainty than we report and publication bias assessment was strongly suggestive of a bias in favour of positive studies. The current analysis therefore suggests that the small effects seen with CD in this and previous meta-analyses are probably a cumulative consequence of several biases we have outlined, including confounding effect and publication bias.

Longitudinal impact of sleep on overweight and obesity in children and adolescents: a systematic review and bias-adjusted meta-analysis.

Short sleep duration is considered a potential risk for overweight/obesity in childhood and adolescence. However, most of the evidence on this topic is obtained from cross-sectional studies; therefore, the nature and extent of the longitudinal associations are unclear. This study explores the prospective association between short sleep and overweight/obesity in young subjects. The MEDLINE, EMBASE, Pubmed, and CINAHL databases were searched for English-language articles, published until May 2014, reporting longitudinal association between sleep and body mass index (BMI) in children and adolescents. Recommendations of the Sleep Health Foundation were used to standardize reference sleep duration. Sleep category, with sleep duration less than the reference sleep, was considered as the short sleep category. Meta-analysis was conducted to explore the association between short sleep and overweight/obesity. A review of 22 longitudinal studies, with subjects from diverse backgrounds, suggested an inverse association between sleep duration and BMI. Meta-analysis of 11 longitudinal studies, comprising 24,821 participants, revealed that subjects sleeping for short duration had twice the risk of being overweight/obese, compared with subjects sleeping for long duration (odds ratio 2.15; 95% confidence interval: 1.64-2.81). This study provides evidence that short sleep duration in young subjects is significantly associated with future overweight/obesity.

Putting the diabetes risk due to statins in perspective: a re-evaluation using the complementary outcome.

AIMS: Statins are used extensively to treat dyslipidemia and have been associated with significant clinical benefit that increases with dose. However, recent studies have associated statins with an excess risk of developing diabetes mellitus, which may offset the clinical benefit to patients. Adverse events related to intensive-dose statin therapy were revisited in light of recent data regarding the use of relative risks. DATA SYNTHESIS: A meta-analysis was replicated with the event of interest redefined as the complementary outcome (no-onset of diabetes). Five randomised controlled trials that compared the risk of intense-dose with moderate-dose of statin therapy for the onset of diabetes with a follow-up greater than 12 months were included in the analysis. A reduction in the risk for no-onset of diabetes was found when intensive-dose statin therapy was compared with moderate-dose statin therapy, revealing a relative risk of 0.9908 (95%CI: 0.9849-0.99679). Over two years, one more patient was harmed by diabetes onset for every 237 patients exposed to intensive-dose statin therapy (95%CI: 123-3847) compared with standard dose statin therapy. CONCLUSIONS: Statins are associated with only a very small increase in risk of diabetes mellitus. Previous research selected the outcomes with the lower baseline risks and therefore the actual risk associated with statins has been largely over-estimated.

Gestational weight gain in relation to offspring obesity over the life course: a systematic review and bias-adjusted meta-analysis.

Gestational weight gain (GWG) is considered one of the risk factors for future obesity in the offspring. However, the direction and strength of this association at different periods of offspring life is relatively unknown. This study investigates whether excess or inadequate maternal GWG during pregnancy influences the risk of offspring obesity at different stages in life. A systematic review of published articles was undertaken after a comprehensive search of different databases, and extracted data were meta-analysed. To quantify offspring obesity estimates in relation to GWG, we stratified obesity estimates within three life stages of the offspring age: <5 years, 5 to <18 years and 18+ years. Our meta-analysis showed that, compared with offspring of women with adequate GWG, offspring of women who gained inadequate gestational weight were at a decreased risk of obesity (relative risk [RR]: 0.86; 95% confidence interval [CI]: 0.78-0.94), and offspring of women who gained excess weight were at an increased risk of obesity (RR: 1.40; 95% CI: 1.23-1.59). These relationships were similar after stratification by life stage. Findings of this study therefore suggest that excess GWG does influence offspring obesity over the short- and long-term, and should therefore be avoided.

Randomized clinical trial of the impact of insulin therapy on liver function in patients undergoing major liver resection.

BACKGROUND: Postoperative liver dysfunction is the major source of morbidity and mortality in patients undergoing partial hepatectomy. This study tested the benefits of a metabolic support protocol based on insulin infusion, for reducing liver dysfunction following hepatic resection. METHODS: Consecutive consenting patients scheduled for liver resection were randomized to receive preoperative dextrose infusion followed by insulin therapy using the hyperinsulinaemic normoglycaemic clamp protocol (n = 29) or standard therapy (control group, n = 27). Patients in the insulin therapy group followed a strict dietary regimen for 24 h before surgery. Intravenous dextrose was started at 2 mg per kg per min the night before and continued until surgery. Hyperinsulinaemic therapy for a total of 24 h was initiated at 2 munits per kg per min at induction of anaesthesia, and continued at 1 munit per kg per min after surgery. Normoglycaemia was maintained (3.5-6.0 mmol/l). Control subjects received no additional dietary supplement and a conventional insulin sliding scale during fasting. All patients were tested serially to evaluate liver function using the Schindl score. Liver tissue samples were collected at two time points during surgery to measure glycogen levels. RESULTS: Demographics were similar in the two groups. More liver dysfunction occurred in the control cohort (liver dysfunction score range 0-8 versus 0-4 with insulin therapy; P = 0.031). Median (interquartile range) liver glycogen content was 278 (153-312) and 431 (334-459) µmol/g respectively (P = 0.011). The number of complications rose with increasing severity of postoperative liver dysfunction (P = 0.032) CONCLUSION: The glucose-insulin protocol reduced postoperative liver dysfunction and improved liver glycogen content. REGISTRATION NUMBER: NCT00774098 (http://www.clinicaltrials.gov).

Smoking behaviour in pregnancy and its impact on smoking cessation at various intervals during follow-up over 21 years: a prospective cohort study.

OBJECTIVE: To determine whether mothers who quit or reduce their level of smoking in pregnancy comprise a group of health-conscious women who are disproportionally likely to adopt a healthier smoking lifestyle in the medium to longer term, compared with women who continue to smoke during pregnancy. DESIGN: A prospective cohort study. SETTING: A public hospital in Australia. POPULATION: A cohort of 6703 individual mothers who completed both initial phases of data collection in 1981-1983; mothers who smoked daily (2992) before pregnancy were included in this study. METHODS: Mothers were interviewed at 3-5 days post-delivery, 6 months, 5 years, 14 years and 21 years to determine their smoking status. An inverse probability-weighted Poisson regression with a robust error variance was fitted to the data using a log-link function and a binary response variable for smoking outcome, and adjusting for several possible confounding factors. MAIN OUTCOME MEASURE: Smoking cessation at several follow-up points, for up to 21 years. RESULTS: Of the mothers who smoked daily before pregnancy, 12, 23, 37 and 41% reported having ceased smoking at 6 months and at 5, 14 and 21 years, respectively. The decision to quit smoking during pregnancy was found to be independently associated with a higher rate ratio (RR) of smoking cessation at 6 months (RR 30.60, 95% CI 20.50-45.69), 5 years (RR 4.36; 95% CI 3.61-5.27), 14 years (RR 2.42, 95% CI 2.12-2.75) and 21 years (RR 1.86; 95% CI 1.60-2.15), after adjusting for several possible confounding factors. CONCLUSIONS: Pregnancy appears to be an opportunity for successfully quitting smoking, regardless of socio-economic circumstances or demographic background.

Systematic review and meta-analysis of the effect of North American working hours restrictions on mortality and morbidity in surgical patients.

BACKGROUND: Short duty hours, imposed by the Accreditation Council of Graduate Medical Education (ACGME) regulations, have been claimed to be associated with loss of continuity of care among surgical patients, leading to a potentially increased risk of adverse surgical outcomes. This systematic review and meta-analysis assessed the strength of associations between duty hour restrictions and morbidity and mortality of various surgical procedures. METHODS: MEDLINE, Embase, BIOSIS Previews(®), the Education Resources Information Center and the Cochrane Central Register of Controlled Trials (January 2000 to September 2009) were searched, and reports screened to identify comparative studies of mortality and morbidity before and after the introduction of ACGME regulation periods. Random-effects (RE) and quality-effects (QE) meta-analyses were performed to determine the risk of morbidity or death associated with long duty hours compared with shorter duty hours. Results are presented as odds ratio (OR) with 95 per cent confidence interval. RESULTS: A total of 19 data sets (10 articles), including 730,648 subjects in the mortality studies and 64,346 in the morbidity studies, were analysed. Long duty hours were associated with a non-significantly increased risk of death compared with shorter duty hours (OR 1·28, 0·94 to 1·73). There was no difference in morbidity between the two groups (OR 1·03, 0·67 to 1·57). Mortality associations were generally stronger for general surgery, more recent studies and higher-quality studies. Heterogeneity was evident among the studies included. CONCLUSION: The reduction in working hours has not affected patient care negatively in terms of demonstrable differences in morbidity and mortality. However, it cannot be distinguished whether this effect is actually due to a non-detrimental effect of the reduction in working hours or whether any such detriment is offset by continually improving patient care and increased surgical supervision.

Screening for diabetes in Kuwait and evaluation of risk scores.

This study aimed to develop a simple risk score to identify individuals at high risk for undiagnosed diabetes in the Kuwaiti adult population and to assess the performance of previously published diabetes risk scores. A cross-sectional survey with a sample of 562 Kuwaiti public sector employees was carried out in 2007. Data were collected through a self-administered questionnaire and a blood glucose test. The overall prevalence of diabetes using American Diabetes Association 2003 criteria was 21.4% (4.1% newly detected). The proposed score had 87% sensitivity and 64% specificity in predicting undetected diabetes using only 4 questions (age, waist circumference, use of blood pressure medication and diabetes in a sibling). Most previously published risk scores were not applicable to this population.

Screening for diabetes in Kuwait and evaluation of risk scores

This study aimed to develop a simple risk score to identify individuals at high risk for undiagnosed diabetes in the Kuwaiti adult population and to assess the performance of previously published diabetes risk scores. A cross-sectional survey with a sample of 562 Kuwaiti public sector employees was carried out in 2007. Data were collected through a self-administered questionnaire and a blood glucose test. The overall prevalence of diabetes using American Diabetes Association 2003 criteria was 21.4% [4.1% newly detected]. The proposed score had 87% sensitivity and 64% specificity in predicting undetected diabetes using only 4 questions [age, waist circumference, use of blood pressure medication and diabetes in a sibling]. Most previously published risk scores were not applicable to this population

Normal measurement of orbital structures: implications for the assessment of Graves' ophthalmopathy.

Compute tomography anatomy of the orbits is well described, but only a few reports are available on normal measurements of the extraocular muscles (EOM) and globe position (GP). We obtained CT images from patients who were referred to our department for CT of the paranasal sinuses using a standard protocol for evaluation of normal orbital measurements. Our study suggests that optimum results are attained with the use of a coronal scan at a window level and width setting that results in an optimum image at the maximum muscle width for assessment of EOM and an axial scan at the mid-GP for GP and interzygomatic line. Based on our normal values, a right-to-left ratio of more than 1.4 for EOM diameter or 1.2 for GP is indicative of asymmetry. An absolute diameter of EOM > 8 mm and GP < 2 mm are abnormal.

Optimal use and interpretation of the aldosterone renin ratio to detect aldosterone excess in hypertension.

With the introduction of the aldosterone/renin ratio as a screening test, the detection rate of primary aldosteronism has increased considerably. Nevertheless, no consensus has so far been reached regarding the cutoff points, operating characteristics or indeed even the reference values for reporting the aldosterone/renin ratio using plasma active renin (ng/l or mU/l) measured by immunoradiometric assay. We review the characteristics of this ratio in normal individuals, essential hypertension and primary hyperaldosteronism in an attempt to reach an agreement regarding its optimum use and interpretation - both using the renin activity or concentration. It seems that the optimal cutoff for patients with primary aldosteronism is above 30 ng/dl per mug/l/h or 800 pmol/l per mug/l/h or 130 pmol/ng or 80 pmol/mU. We explore enhancing measures such as captopril loading or use with a plasma aldosterone cutoff as well as pitfalls with the test such as confounding medications or the need for confirmatory testing. For the latter, demonstration of autonomous aldosterone production via salt loading is widely used, but may not be most advantageous and may even be contraindicated in patients with severe hypertension. The renin stimulation test may be an alternative being safe, well tolerated, and cost effective.

Ovarian steroids modulate neuroendocrine dysfunction in polycystic ovary syndrome.

OBJECTIVE: Neuroendocrine dysfunction in polycystic ovary syndrome (PCOS) was addressed by studying the steroid hormone changes in women with PCOS with either high or normal LH levels leading to inferences regarding the primacy of elevated LH in the pathophysiology of PCOS. METHODS: A cross-sectional study was designed in an academic clinical facility involving 234 women with PCOS. Patients were divided into two groups based on an LH/FSH ratio < or >1 and hormonal and metabolic studies were performed in both groups. Factors were determined by binomial logistic regression that predicted group membership of these women. RESULTS: Higher follicular phase estradiol (E2) and androstenedione (A4) levels as well as greater insulin sensitivity were the only factors that predicted the presence of neuroendocrine dysfunction with elevated A4 being necessary for neuroendocrine dysfunction. CONCLUSIONS: It was concluded that uncoupling of hypothalamic E2 inhibition by elevated ovarian A4 associated with E2 related sensitization of pituitary LH leads to neuroendocrine dysfunction in PCOS.

Pharmacodynamic optimization of warfarin therapy II.

A pharmacodynamic (E(max)) model for optimizing warfarin initiation had previously been reported. This study assessed the validity of this model, adjusted further for age in both the initial cohort and another cohort distinct from that used for the formulation of the model. Thirty-one patients undergoing oral anticoagulation for mainly cardiac indications were recruited from Kuala Lumpur. Thirty-four patients undergoing oral anticoagulation for deep vein thrombosis were recruited from Cambridge. They were studied for their anticoagulant response to the initiation of warfarin. The former were intuitively dosed after a 2-day loading of 10 mg warfarin/d. The latter all were commenced on warfarin via a standard 4-day induction protocol of Fennerty et al that allows early estimation of the required maintenance dose. The actual maintenance doses in both cohorts were compared with their predicted doses on the initiation of therapy that was calculated both from this model and from the induction protocol of Fennerty et al. The third day's international normalized ratio and age combination was additive in terms of their influence on the maintenance dose. The predictive model in both cohorts returned similar results and explained at least two thirds of the interindividual variability in warfarin maintenance dose requirements, whereas the induction protocol of Fennerty et al explained only one third of this interindividual variability. Use of this model in the form of the included nomogram should be able to decrease both the occurrence of either under- or overanticoagulation as well as the time taken to initiate treatment and decide the correct maintenance dose during the initiation of oral anticoagulation with warfarin in hospitals. A prospective evaluation of the nomogram is recommended.