Record linkage between hospital discharges and mortality registries for motor neuron disease case ascertainment for the Spanish National Rare Diseases Registry

Our objective was to analyse the coverage of hospital discharge data and the mortality registry (MR) of La Rioja to ascertain motor neuron disease (MND) cases to be included in the Spanish National Rare Diseases Registry. MND cases that occurred in La Rioja during the period 1996-2011 were selected from hospital discharge data and the MR by means of the International Classification of Diseases. Review of the medical histories was carried out to confirm the causes of death reported. Characteristics of the population with MND were analysed. A total of 133 patients with MND were detected in La Rioja during the period 1996-2011; 30.1% were only recorded in the hospital discharges data, 12.0% only in the MR, and 57.9% were recorded by both databases. Medical records revealed a miscoding of patients who had been diagnosed with progressive supranuclear palsy but were recorded in the MR with an MND code. In conclusion, the hospital discharges data and the MR appear to be complementary and are valuable databases for the Spanish National Rare Diseases Registry when MNDs are properly codified. Nevertheless, it would be advisable to corroborate the validity of the MR as data source since the miscoding of progressive supranuclear palsy has been corrected.

Body mass index in childhood and adult risk of primary liver cancer

BACKGROUND & AIMS

Childhood overweight increases the risk of early development of non-alcoholic fatty liver disease, which may predispose to carcinogenesis. We investigated if childhood body size during school ages was associated with the risk of primary liver cancer in adults.

METHODS

A cohort of 285,884 boys and girls, born 1930 through 1980, who attended school in Copenhagen, were followed from 1977 to 31 December 2010. Their heights and weights were measured by school doctors or nurses at ages 7 through 13 years. Body mass index (BMI) z-scores were calculated from an internal age- and sex-specific reference. Information on liver cancer was obtained from the National Cancer Registry. Hazard ratios and 95% confidence intervals (95% CI) of liver cancer were estimated by Cox regression.

RESULTS

During 6,963,105 person-years of follow-up, 438 cases of primary liver cancer were recorded. The hazard ratio (95% CI) of adult liver cancer was 1.20 (1.07-1.33) and 1.30 (1.16-1.46) per 1-unit BMI z-score at 7 years and 13 years of age, respectively. Similar associations were found in boys and girls, for hepatocellular carcinoma only, across years of birth, and after accounting for diagnoses of viral hepatitis, alcohol-related disorders, and biliary cirrhosis.

CONCLUSIONS

Higher BMI in childhood increases the risk of primary liver cancer in adults. In view of the high case fatality of primary liver cancer, this result adds to the future negative health outcomes of the epidemic of childhood overweight, reinforcing the need for its prevention.

Risk of cancer in patients with inflammatory bowel diseases: a nationwide population-based cohort study with 30 years of follow-up evaluation

BACKGROUND & AIMS

Data regarding the risk of gastrointestinal and extraintestinal cancers in Crohn's disease (CD) and ulcerative colitis (UC) are needed to understand the clinical course of inflammatory bowel diseases (IBDs) and their treatments.

METHODS

We performed a nationwide historical cohort study using Danish health care databases. We identified patients with a diagnosis of CD or UC, recorded from 1978 through 2010, and followed them up until the first occurrence of cancer, death, or emigration. We used standardized incidence ratios (SIRs) to compare cancer incidence in CD and UC patients with that expected in the general population.

RESULTS

Excluding cancers diagnosed within 1 year of IBD diagnosis, 772 cases of invasive cancer occurred among 13,756 patients with CD (SIR, 1.3; 95% confidence interval [CI], 1.2-1.4) and 2331 occurred among 35,152 patients with UC (SIR, 1.1; 95% CI, 1.0-1.1). CD was associated weakly with gastrointestinal cancers (SIR, 1.2; 95% CI, 1.0-1.4) and extraintestinal cancers (SIR, 1.3; 95% CI, 1.2-1.4), with the strongest associations for hematologic malignancies (SIR, 1.9; 95% CI, 1.5-2.3), smoking-related cancers (SIR, 1.5; 95% CI, 1.3-1.8), and melanoma (SIR, 1.4; 95% CI, 1.0-1.9). Associations between UC and gastrointestinal and extraintestinal cancers were weaker (SIR, 1.1; 95% CI, 1.0-1.2; and SIR, 1.1; 95% CI, 1.0-1.1, respectively). The relative risk of extraintestinal cancers among patients with IBD was relatively stable over time, although the risk of gastrointestinal cancers decreased.

CONCLUSIONS

Patients with IBD, particularly CD, are at increased risk for gastrointestinal and extraintestinal malignancies. The relative risk of gastrointestinal malignancy has decreased since 1978, without a concomitant increase in the risk of nongastrointestinal malignancy.

Controlled vocabularies and ontologies in proteomics: overview, principles and practice

This paper focuses on the use of controlled vocabularies (CVs) and ontologies especially in the area of proteomics, primarily related to the work of the Proteomics Standards Initiative (PSI). It describes the relevant proteomics standard formats and the ontologies used within them. Software and tools for working with these ontology files are also discussed. The article also examines the "mapping files" used to ensure correct controlled vocabulary terms that are placed within PSI standards and the fulfillment of the MIAPE (Minimum Information about a Proteomics Experiment) requirements. This article is part of a Special Issue entitled: Computational Proteomics in the Post-Identification Era. Guest Editors: Martin Eisenacher and Christian Stephan.

A population-based cohort study of pregnancy outcomes among women with primary sclerosing cholangitis

BACKGROUND & AIMS

Studies of primary sclerosing cholangitis (PSC) and pregnancy outcomes have been limited in size and have been inadequate to rule out excess risks. We examined pregnancy outcomes among women with PSC.

METHODS

Women with PSC were identified from inpatient and hospital-based outpatient data in the Swedish National Patient Register. Through linkage with the Medical Birth Register, we identified 229 singleton births, from 1987 through 2009, to women with PSC before delivery. These were compared with 2,304,863 births to women without a diagnosis of PSC. We used logistic regression, adjusted for maternal age, smoking, education, parity, and year of birth, to calculate adjusted prevalence odds ratios (aPORs) for adverse pregnancy outcomes.

RESULTS

Maternal PSC was associated with a 3.63-fold increase in preterm birth (95% confidence interval [CI] for aPOR, 2.35-5.61) as well as an increased risk of cesarean section (aPOR, 2.18; 95% CI, 1.50-3.17). We found no increased risk based on analyses of the 5-minute Apgar score, small for gestational age, stillbirths, or neonatal deaths. Maternal PSC was not a risk factor for congenital abnormalities (aPOR, 1.12; 95% CI, 0.56-2.22). Stratification by inflammatory bowel disease status did not affect the risk estimates more than marginally.

CONCLUSIONS

Maternal PSC is associated with both preterm birth and cesarean section but not with congenital malformation or other adverse outcomes of pregnancy. Pregnancy should not be discouraged in women with PSC.

ADHD, stimulant treatment in childhood and subsequent substance abuse in adulthood - a naturalistic long-term follow-up study

The purpose of the study was to estimate the risk of substance use disorder (SUD) and alcohol abuse in adulthood among children and adolescents with attention-deficit hyperactivity disorder (ADHD) compared to the background population. Furthermore, to examine whether the age at initiation and duration of stimulant treatment in childhood predicts SUD and alcohol abuse in adulthood. 208 youths with ADHD (183 boys; 25 girls) were followed prospectively. Diagnoses of SUD and alcohol abuse were obtained from The Danish Psychiatric Central Register. The relative risk (RR) of SUD and alcohol abuse for cases with ADHD, compared to the background population was 7.7 (4.3-13.9) and 5.2 (2.9-9.4), respectively. Female gender, conduct disorder in childhood and older age at initiation of stimulant treatment increased the risk of later SUD and alcohol abuse. Our results warrant increased focus on the possibly increased risk of substance abuse in females with ADHD compared to males with ADHD.

A systematic review of validated methods to capture myopericarditis using administrative or claims data

PURPOSE

To identify algorithms that can capture incident cases of myocarditis and pericarditis in administrative and claims databases; these algorithms can eventually be used to identify cardiac inflammatory adverse events following vaccine administration.

METHODS

We searched MEDLINE from 1991 to September 2012 using controlled vocabulary and key terms related to myocarditis. We also searched the reference lists of included studies. Two investigators independently assessed the full text of studies against pre-determined inclusion criteria. Two reviewers independently extracted data regarding participant and algorithm characteristics as well as study conduct.

RESULTS

Nine publications (including one study reported in two publications) met criteria for inclusion. Two studies performed medical record review in order to confirm that these coding algorithms actually captured patients with the disease of interest. One of these studies identified five potential cases, none of which were confirmed as acute myocarditis upon review. The other study, which employed a search algorithm based on diagnostic surveillance (using ICD-9 codes 420.90, 420.99, 422.90, 422.91 and 429.0) and sentinel reporting, identified 59 clinically confirmed cases of myopericarditis among 492,671 United States military service personnel who received smallpox vaccine between 2002 and 2003. Neither study provided algorithm validation statistics (positive predictive value, sensitivity, or specificity).

CONCLUSIONS

A validated search algorithm is currently unavailable for identifying incident cases of pericarditis or myocarditis. Several authors have published unvalidated ICD-9-based search algorithms that appear to capture myocarditis events occurring in the context of other underlying cardiac or autoimmune conditions.

A systematic review of validated methods for identifying Bell's palsy using administrative or claims data

PURPOSE

To identify and assess billing, procedural, or diagnosis code, or pharmacy claims-based algorithms used to identify Bell's palsy in administrative and claims databases.

METHODS

We searched the MEDLINE database via PubMed from 1991 to September 2012 using controlled vocabulary and key terms related to Bell's palsy. We also searched the reference lists of included studies. Two investigators independently assessed the full text of studies against pre-determined inclusion criteria. Two reviewers independently extracted data regarding participant and algorithm characteristics and assessed a study's methodologic rigor.

RESULTS

One study identified Bell's palsy using an algorithm that included ICD-9 code 351.x and H-ICDA code 350.x, and two other studies analyzed a dataset for ICD-9 code 351.0. The positive predictive values of these studies were 0.81 and 0.88, based on case adjudication of ICD-9 matches. Two further studies calculated incidence rates without validation of their methods, also including ICD-9 code 351.0. No study reported the sensitivity of algorithms to identify Bell's palsy.

CONCLUSIONS

Few publications used rigorous methods to identify a validated algorithm that could identify cases of Bell's palsy from an administrative database. The best evidence from two different datasets in the literature addressed in this review used ICD-9 code 351.0 or a collection of ICD-9 codes 351.x for facial nerve disorders including Bell's palsy, along with other ICD-9 and H-ICDA codes for facial weakness. Each study had acceptable PPV, suggesting that ICD-9 based-algorithms have some utility in detecting Bell's palsy cases.

Leptin receptor Arg109 homozygotes display decreased total mortality as well as lower incidence of cardiovascular disease and related death

Two leptin receptor single nucleotide polymorphisms, Lys109Arg and Gln223Arg, have been shown to associate with several risk factors for cardiovascular disease. In addition, we have previously shown that Arg109 and Arg223 homozygotes displayed lower intima-media thickness in our well-defined OPERA (Oulu Project Elucidating Risk of Atherosclerosis) study. This current research investigated the impact of these LEPR polymorphisms on cardiovascular events and related death as well as to total mortality in the 19-year follow-up of OPERA. Subjects were randomly selected, middle-aged drug-treated hypertensives and their age- and sex-matched control subjects recruited to the OPERA study between 1990 and 1993. Mortality and hospital events of 1045 subjects were followed up until 2009. A total of 151 coronary heart disease (CHD) and 211 cardiovascular disease (CVD) events or deaths including 58 CHD and 69 CVD deaths occurred. Furthermore, during this follow-up, a total of 165 subjects died. Logistic regression analysis was performed to assess the impact of Lys109Arg and Gln223Arg on the events and death. Further modeling was performed with Cox regression for Lys109Arg. The logistic regression analysis revealed a significant protective impact of Arg109Arg genotype on CHD (OR 0.433; CI 95% 0.217-0.863) and CVD (OR 0.540; CI 95% 0.309-0.942) events or death as well as on total mortality (OR 0.390; CI 95% 0.196-0.775) when adjusted with age, sex and study group. Even after further adjustment with BMI, smoking status, systolic blood pressure and low-density lipoprotein cholesterol, the protective effect of Arg109Arg on CHD events or death and total mortality still remained statistically significant (OR 0.463; CI 95% 0.230-0.931 and OR 0.442; CI 95% 0.218-0.896, respectively). Arg109Arg was also shown to confer protection against CHD mortality (HR 0.224; CI95% 0.055-0.919) and overall mortality (HR 0.413; CI95% 0.218-0.783) also in Cox regression analysis. In conclusion, the Arg109Arg genotype of LEPR seems to be protective from cardiovascular events and death and this phenomenon seems to be independent of the traditional risk factors for atherosclerosis.

International Classification of Diseases Codes and their Use in Dentistry

The deadline for replacing International Classification of Diseases, 9th edition (ICD-9) code sets with the newer ICD-10 code sets, used for the reporting of medical diagnoses and inpatient hospital procedures, was recently updated to occur at a date no sooner than October 1, 2015; with October 1, 2015 being the likely implementation date. The transition to ICD-10 is mandatory for all entities covered by the Health Insurance Portability Accountability Act (HIPAA). This review will provide a brief history of the development of ICD codes; provide an overview of ICD-9/ICD-9-Clinical Modification (CM) and ICD-10/ ICD-10-CM/Procedural Coding System (PCS) codes; provide information on the conversion of ICD-9-CM to ICD-10-CM/PCS codes; and provide information on the uses of ICD codes in dentistry in the United States.

Exploration of ICD-9-CM coding of chronic disease within the Elixhauser Comorbidity Measure in patients with chronic heart failure

INTRODUCTION

International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes capture comorbidities that can be used to risk adjust nonrandom patient groups. We explored the accuracy of capturing comorbidities associated with one risk adjustment method, the Elixhauser Comorbidity Measure (ECM), in patients with chronic heart failure (CHF) at one Veterans Affairs (VA) medical center. We explored potential reasons for the differences found between the original codes assigned and conditions found through retrospective review.

METHODS

This descriptive, retrospective study used a cohort of patients discharged with a principal diagnosis coded as CHF from one VA medical center in 2003. One admission per patient was used in the study; with multiple admissions, only the first admission was analyzed. We compared the assignment of original codes assigned to conditions found in a retrospective, manual review of the medical record conducted by an investigator with coding expertise as well as by physicians. Members of the team experienced with assigning ICD-9-CM codes and VA coding processes developed themes related to systemic reasons why chronic conditions were not coded in VA records using applied thematic techniques.

RESULTS

In the 181-patient cohort, 388 comorbid conditions were identified; 305 of these were chronic conditions, originally coded at the time of discharge with an average of 1.7 comorbidities related to the ECM per patient. The review by an investigator with coding expertise revealed a total of 937 comorbidities resulting in 618 chronic comorbid conditions with an average of 3.4 per patient; physician review found 872 total comorbidities with 562 chronic conditions (average 3.1 per patient). The agreement between the original and the retrospective coding review was 88 percent. The kappa statistic for the original and the retrospective coding review was 0.375 with a 95 percent confidence interval (CI) of 0.352 to 0.398. The kappa statistic for the retrospective coding review and physician review was 0.849 (CI, 0.823-0.875). The kappa statistic for the original coding and the physician review was 0.340 (CI, 0.316-0.364). Several systemic factors were identified, including familiarity with inpatient VA and non-VA guidelines, the quality of documentation, and operational requirements to complete the coding process within short time frames and to identify the reasons for movement within a given facility.

CONCLUSION

Comorbidities within the ECM representing chronic conditions were significantly underrepresented in the original code assignment. Contributing factors potentially include prioritization of codes related to acute conditions over chronic conditions; coders' professional training, educational level, and experience; and the limited number of codes allowed in initial coding software. This study highlights the need to evaluate systemic causes of underrepresentation of chronic conditions to improve the accuracy of risk adjustment used for health services research, resource allocation, and performance measurement.

Validation of diagnostic codes for intussusception and quantification of childhood intussusception incidence in Ontario, Canada: a population-based study

OBJECTIVES

To validate an algorithm to identify cases of intussusception using the health administrative data of Ontario, Canada, and to apply the algorithm to estimate provincial incidence of intussusception, preceding the introduction of the universal rotavirus vaccination program.

STUDY DESIGN

We determined the accuracy of various combinations of diagnostic, procedural, and billing codes using the chart-abstracted diagnoses of patients of the Children's Hospital of Eastern Ontario as the reference standard. We selected an algorithm that maximized positive predictive value while maintaining a high sensitivity and used it to ascertain annual incidence of intussusception for fiscal years 1995-2010. We explored temporal trends in incidence using Poisson regression.

RESULTS

The selected algorithm included only the International Classification of Diseases (ICD)-9 or ICD-10 code for intussusception in the hospitalization database and was sensitive (89.3%) and highly specific (>99.9%). The positive predictive value of the ICD code was 72.4%, and the negative predictive value was >99.9%. We observed the highest mean incidence (34 per 100000) in male children <1 year of age. Temporal trends in incidence varied by age group. There was a significant mean decrease in incidence of 4% per year in infants (<1 year) until 2004 and rates stabilized thereafter.

CONCLUSIONS

We have demonstrated that intussusception can be accurately identified within health administrative data using validated algorithms. We have described changes in temporal trends in intussusception incidence in Ontario and established a baseline to allow ongoing monitoring as part of vaccine safety surveillance.

The epidemiology of cardiovascular diseases in sub-Saharan Africa: the Global Burden of Diseases, Injuries and Risk Factors 2010 Study

The epidemiology of cardiovascular diseases in sub-Saharan Africa is unique among world regions, with about half of cardiovascular diseases (CVDs) due to causes other than atherosclerosis. CVD epidemiology data are sparse and of uneven quality in sub-Saharan Africa. Using the available data, the Global Burden of Diseases, Risk Factors, and Injuries (GBD) 2010 Study estimated CVD mortality and burden of disease in sub-Saharan Africa in 1990 and 2010. The leading CVD cause of death and disability in 2010 in sub-Saharan Africa was stroke; the largest relative increases in CVD burden between 1990 and 2010 were in atrial fibrillation and peripheral arterial disease. CVD deaths constituted only 8.8% of all deaths and 3.5% of all disability-adjusted life years (DALYs) in sub-Sahara Africa, less than a quarter of the proportion of deaths and burden attributed to CVD in high income regions. However, CVD deaths in sub-Saharan Africa occur at younger ages on average than in the rest of the world. It remains uncertain if increased urbanization and life expectancy in some parts of sub-Saharan African nations will transition the region to higher CVD burden in future years.

Childhood epilepsy and maternal antibodies to microbial and tissue antigens during pregnancy

INTRODUCTION

Several epidemiologic studies show associations between mother's infections during pregnancy and an increased risk of mental and neurological disorders in the offspring. Such associations could be due to the direct or indirect effects of infectious agents, including immune responses to infectious agents that display molecular mimicry with host antigens. We measured a range of antigen-specific maternal IgG antibodies to examine if any were associated with risk for childhood epilepsy in offspring.

METHODS

We used a case-cohort design within the Danish National Birth Cohort (DNBC) to examine maternal IgG antibodies to 25 microbial and tissue antigens during pregnancy and their association with the risk of epilepsy in offspring. The source population of this study was 68,250 live born singletons with up to 10 years of follow up. We randomly identified a sample of 282 children as a subcohort and included 275 children with a verified diagnosis of epilepsy as cases. Maternal antibodies were categorized into 6 groups (<50, 50-59, 60-69, 70-79, 80-89, ≥90 percentile) according to the level in the subcohort. We used a Prentice-weighted Cox regression model to estimate the hazard ratio (HR) and 95% confidence interval (CI) for epilepsy according to measured antibodies.

RESULTS

Higher levels of maternal antibodies against herpes simples virus type 1 (anti-HSV1) were associated with a slightly higher risk of childhood epilepsy (HR for trend=1.09, 95% CI: 0.99-1.21), while higher levels of maternal antibodies against pneumococcal polysaccharide 18 (anti-PnPS18) were associated with a lower risk of childhood epilepsy (HR for trend=0.90, 95% CI: 0.81-1.01). Among the subtypes, a significantly higher risk associated with anti-HSV1 antibodies was seen for childhood absence epilepsy (HR for trend=2.08, 95% CI: 1.12-3.85) and for epileptic encephalopathies (HR for trend=1.49, 95% CI: 1.01-2.22). The significantly lower risk associated with anti-PnPS18 antibodies was observed for infantile spasms (HR for trend=0.47, 95% CI: 0.27-0.83).

CONCLUSIONS

Maternal anti-HSV1and anti-PnPS18 antibodies during pregnancy may be associated with the risk of epilepsy in offspring, but any potential etiologic and preventative implications of these associations warrant further exploration.

Development and evaluation of an ensemble resource linking medications to their indications

OBJECTIVE

To create a computable MEDication Indication resource (MEDI) to support primary and secondary use of electronic medical records (EMRs).

MATERIALS AND METHODS

We processed four public medication resources, RxNorm, Side Effect Resource (SIDER) 2, MedlinePlus, and Wikipedia, to create MEDI. We applied natural language processing and ontology relationships to extract indications for prescribable, single-ingredient medication concepts and all ingredient concepts as defined by RxNorm. Indications were coded as Unified Medical Language System (UMLS) concepts and International Classification of Diseases, 9th edition (ICD9) codes. A total of 689 extracted indications were randomly selected for manual review for accuracy using dual-physician review. We identified a subset of medication-indication pairs that optimizes recall while maintaining high precision.

RESULTS

MEDI contains 3112 medications and 63 343 medication-indication pairs. Wikipedia was the largest resource, with 2608 medications and 34 911 pairs. For each resource, estimated precision and recall, respectively, were 94% and 20% for RxNorm, 75% and 33% for MedlinePlus, 67% and 31% for SIDER 2, and 56% and 51% for Wikipedia. The MEDI high-precision subset (MEDI-HPS) includes indications found within either RxNorm or at least two of the three other resources. MEDI-HPS contains 13 304 unique indication pairs regarding 2136 medications. The mean±SD number of indications for each medication in MEDI-HPS is 6.22 ± 6.09. The estimated precision of MEDI-HPS is 92%.

CONCLUSIONS

MEDI is a publicly available, computable resource that links medications with their indications as represented by concepts and billing codes. MEDI may benefit clinical EMR applications and reuse of EMR data for research.

Screening patterns within organized programs and survival of Italian women with invasive cervical cancer

OBJECTIVES

To evaluate screening patterns within organized cervical screening programs (OCSPs) and survival of women with invasive cervical cancer (ICC).

METHODS

A population-based study was conducted in Italian areas covered by cancer registries and OCSPs. The study included all women aged 25-65 years diagnosed with ICC between 1995 and 2008, and their screening histories within OCSPs were retrieved. Hazard ratios (HR) of death and 95% confidence intervals (CI) were computed according to screening pattern, using Cox models adjusted for age, ICC stage, and major confounders.

RESULTS

Among 3268 women with ICC, 20% were never-invited to OCSP, 36% were never-compliant with OCSP's invitation, 33% were compliant and had a screen-detected ICC within OCSP (i.e., after a positive cytology), and 11% were compliant but had a non-screen-detected ICC. Screen-detected ICCs were more frequently micro-invasive (42%) compared to non-screen-detected ones (14%). Compared to women with screen-detected ICC, the adjusted HRs of death were 1.9 (95% CI 1.5-2.4) for those never-invited, 2.0 (95% CI 1.6-2.5) for never-compliant, and 1.7 (95% CI 1.3-2.4) for compliant women having non-screen-detected ICC.

CONCLUSION

Prolonged survival, beyond down-staging, of women with ICC detected within OCSPs in Italy, further calls for improvements of OCSPs' invitational coverage and participation.

Accuracy of International Classification of Diseases, 9th Revision, Clinical Modification codes for upper gastrointestinal complications varied by position and age: a validation study in a cohort of nonsteroidal anti-inflammatory drugs users in Friuli Venezia Giulia, Italy

PURPOSE

To validate the International Classification of Diseases, 9th Revision, Clinical Modification discharge codes used to identify cases of upper gastrointestinal complications (UGICs) in hospitals of Friuli Venezia Giulia, Italy.

METHODS

Cohort study on the risk of UGIC in users of nonsteroidal anti-inflammatory drugs conducted in Friuli Venezia Giulia between 2001 and 2008. Cases were identified through primary and secondary International Classification of Diseases, 9th Revision Clinical specific codes 531 (gastric ulcer), 532 (duodenal ulcer), 533 (peptic ulcer), 534 (gastrojejunal ulcer), and nonspecific code 578 (gastrointestinal hemorrhage). Potential cases were confirmed through hospital chart review.

RESULTS

The chart retrieval percentage was 98.4%.The positive predictive value (PPV) was 94.3% for primary codes 531 and 532, 79.5% for code 533, 83.1% for code 534, 40.2% for code 578. The PPV for secondary codes was 34.7% but increased to 88.9% and 79.2% when the primary code was for peritonitis or acute post-hemorrhagic anemia, respectively. Validation of secondary codes increased case ascertainment by 4.9%. Endoscopy confirmed 79.4% of cases but only 67.2% of those above age 84 years.

CONCLUSIONS

The PPV was high for specific primary codes and moderate to low for nonspecific primary and secondary codes. The inclusion of confirmed cases identified by nonspecific and secondary codes can be of value in studies that need a complete ascertainment of cases occurring in the study population. In this cohort, not including these cases would underestimate the incidence of UGICs. A potential for case misclassification exists in particular in eldest ages.

Validity of an algorithm to identify osteonecrosis of the jaw in women with postmenopausal osteoporosis in the Danish National Registry of Patients

BACKGROUND

Osteonecrosis of the jaw (ONJ) is an adverse effect of drugs that suppress bone turnover - for example, drugs used for the treatment of postmenopausal osteoporosis. The Danish National Registry of Patients (DNRP) is potentially valuable for monitoring ONJ and its prognosis; however, no specific code for ONJ exists in the International Classification of Diseases 10th revision (ICD-10), which is currently used in Denmark. Our aim was to estimate the positive predictive value (PPV) of an algorithm to capture ONJ cases in the DNRP among women with postmenopausal osteoporosis.

METHODS

We conducted this cross-sectional validation study in the Central and North Denmark Regions, with approximately 1.8 million inhabitants. In total, 54,956 women with postmenopausal osteoporosis were identified from June 1, 2005 through May 31, 2010. To identify women potentially suffering from ONJ, we applied an algorithm based on ICD-10 codes in the DNRP originating from hospital-based departments of oral and maxillofacial surgery (DOMS). ONJ was adjudicated by chart review and defined by the presence of exposed maxillofacial bone for 8 weeks or more, in the absence of recorded history of craniofacial radiation therapy. We estimated the PPV for the overall algorithm and for each separate ICD-10 code used in the algorithm.

RESULTS

Charts were obtained and reviewed for all 60 women with an ICD-10 code potentially representing ONJ. Nineteen potential ONJ cases were confirmed, corresponding to an overall PPV of 32% (95% confidence interval: 20%-45%).

CONCLUSION

Among women with postmenopausal osteoporosis, only about one-third of the potential ONJ cases identified by our ICD-10 based algorithm were confirmed by medical chart review, despite the restriction to patients treated at DOMS. To capture true ONJ cases among women with postmenopausal osteoporosis, alternative approaches are needed.

Underestimation of liver-related mortality in the United States

BACKGROUND & AIMS

According to the National Center for Health Statistics (NCHS), chronic liver disease and cirrhosis is the 12(th) leading cause of death in the United States. However, this single descriptor might not adequately enumerate all deaths from liver disease. The aim of our study was to update data on liver mortality in the United States.

METHODS

Mortality data were obtained from the Rochester Epidemiology Project (1999-2008) and the National Death Registry (1979-2008). Liver-specific mortality values were calculated. In contrast to the narrow NCHS definition, updated liver-related causes of death included other specific liver diagnoses (eg, hepatorenal syndrome), viral hepatitis, and hepatobiliary cancers.

RESULTS

The Rochester Epidemiology Project database contained information on 261 liver-related deaths, with an age- and sex-adjusted death rate of 27.0/100,000 persons (95% confidence interval: 23.7-30.3). Of these, only 71 deaths (27.2%) would have been captured by the NCHS definition. Of cases for which viral hepatitis or hepatobiliary cancer was the cause of death, 96.9% and 94.3% had liver-related immediate causes of death, respectively. In analysis of data from the National Death registry (2008), use of the updated definition increased liver mortality by >2-fold (from 11.7 to 25.7 deaths/100,000, respectively). Using NCHS definitions, liver-related deaths decreased from 18.9/100,000 in 1979 to 11.7/100,000 in 2008-a reduction of 38%. However, using the updated estimate, liver-related deaths were essentially unchanged from 1979 (25.8/100,000) to 2008 (25.7/100,000). Mortality burden was systematically underestimated among non-whites and persons of Hispanic ethnicity.

CONCLUSIONS

Based on analyses of the Rochester Epidemiology Project and National Death databases, liver-related mortality has been underestimated during the past 2 decades in the United States.

Investigation of physicians' attitudes concerning the implementation of international classification systems of diseases as a precondition for evidence-based policy making

This study investigated the main factors affecting physicians' attitudes toward the implementation of international classification systems of diseases. A cross-sectional study was carried out during September 2010. The sample consisted of 158 physicians older than 24 years who were working in a public hospital and a private hospital in central Greece. A questionnaire was drawn up based on the relevant literature. Results indicated that younger physicians and those who worked in the public hospital were most familiar with classification systems. Female physicians and specialists with more than 10 years of experience (since qualifying as a specialist) were not particularly familiar with these systems (58 percent and 56 percent, respectively). Both having a master's degree and attending conferences or seminars had a remarkable impact on knowledge of these systems. Almost all physicians (98 percent) holding a master's degree or a PhD believed that these systems contribute to the compilation of valid statistical data. The majority of physicians would like to use these systems in the future, as long as they are provided with the appropriate training.

ICD-9 tobacco use codes are effective identifiers of smoking status

OBJECTIVE

To evaluate the validity of, characterize the usage of, and propose potential research applications for International Classification of Diseases, Ninth Revision (ICD-9) tobacco codes in clinical populations.

MATERIALS AND METHODS

Using data on cancer cases and cancer-free controls from Vanderbilt's biorepository, BioVU, we evaluated the utility of ICD-9 tobacco use codes to identify ever-smokers in general and high smoking prevalence (lung cancer) clinic populations. We assessed potential biases in documentation, and performed temporal analysis relating transitions between smoking codes to smoking cessation attempts. We also examined the suitability of these codes for use in genetic association analyses.

RESULTS

ICD-9 tobacco use codes can identify smokers in a general clinic population (specificity of 1, sensitivity of 0.32), and there is little evidence of documentation bias. Frequency of code transitions between 'current' and 'former' tobacco use was significantly correlated with initial success at smoking cessation (p<0.0001). Finally, code-based smoking status assignment is a comparable covariate to text-based smoking status for genetic association studies.

DISCUSSION

Our results support the use of ICD-9 tobacco use codes for identifying smokers in a clinical population. Furthermore, with some limitations, these codes are suitable for adjustment of smoking status in genetic studies utilizing electronic health records.

CONCLUSIONS

Researchers should not be deterred by the unavailability of full-text records to determine smoking status if they have ICD-9 code histories.

Fundamental discrepancies in abortion estimates and abortion-related mortality: A reevaluation of recent studies in Mexico with special reference to the International Classification of Diseases

In countries where induced abortion is legally restricted, as in most of Latin America, evaluation of statistics related to induced abortions and abortion-related mortality is challenging. The present article reexamines recent reports estimating the number of induced abortions and abortion-related mortality in Mexico, with special reference to the International Classification of Diseases (ICD). We found significant overestimations of abortion figures in the Federal District of Mexico (up to 10-fold), where elective abortion has been legal since 2007. Significant overestimation of maternal and abortion-related mortality during the last 20 years in the entire Mexican country (up to 35%) was also found. Such overestimations are most likely due to the use of incomplete in-hospital records as well as subjective opinion surveys regarding induced abortion figures, and due to the consideration of causes of death that are unrelated to induced abortion, including flawed denominators of live births. Contrary to previous publications, we found important progress in maternal health, reflected by the decrease in overall maternal mortality (30.6%) from 1990 to 2010. The use of specific ICD codes revealed that the mortality ratio associated with induced abortion decreased 22.9% between 2002 and 2008 (from 1.48 to 1.14 deaths per 100,000 live births). Currently, approximately 98% of maternal deaths in Mexico are related to causes other than induced abortion, such as hemorrhage, hypertension and eclampsia, indirect causes, and other pathological conditions. Therefore, only marginal or null effects would be expected from changes in the legal status of abortion on overall maternal mortality rates. Rather, maternal health in Mexico would greatly benefit from increasing access to emergency and specialized obstetric care. Finally, more reliable methodologies to assess abortion-related deaths are clearly required.

Positive predictive value of the diagnosis coding for vitamin B12 deficiency anemia in the Danish National Patient Register

PURPOSE

The aim of this validation study was to assess the positive predictive value (PPV) of the International Classification of Diseases, 10th revision (ICD-10) diagnosis of vitamin B12 (cobalamin [Cbl]) deficiency anemia in the Danish National Patient Register (DNPR).

PATIENTS AND METHODS

We identified all patients above 18 years of age recorded in the DNPR with a diagnosis of Cbl deficiency anemia (ICD-10 code: D51) admitted to two Danish university hospitals and one Danish regional hospital from 2000 through 2009. We assessed the PPV using biochemical parameters on Cbl deficiency with or without anemia as reference standards. These data were obtained from the Laboratory Information Systems Database. Data on prescriptions with Cbl supplementation drugs were obtained from the Aarhus University Prescription Database.

RESULTS

We identified 1089 patients coded with a Cbl deficiency anemia diagnosis in the DNPR. The PPV was 31.5% (95% confidence interval [CI]: 28.8%-34.3%) and 36.8% (95% CI: 34.0%-39.7%) depending on definitions of Cbl deficiency with anemia. When using Cbl deficiency without anemia as a reference standard, the PPV was 51.3% (95% CI: 48.4%-54.3%). The PPV for Cbl supplemented patients was 22.2% (95% CI: 18.0%-26.9%) and for non-Cbl supplemented patients 63.9% (95% CI: 60.5%-67.3%).

CONCLUSION

The PPVs of the ICD-10 diagnosis coding for Cbl deficiency anemia were generally low in the DNPR. Therefore, this register should be used with caution to study patients with Cbl deficiency anemia.

Positive predictive value of the International Classification of Diseases, 10th edition diagnosis codes for anemia caused by bleeding in the Danish National Registry of Patients

Objective

Valid data on anemia caused by bleeding are needed for epidemiological research and monitoring health care. The Danish National Registry of Patients (DNRP) is a nationwide medical database with information on all Danish residents’ hospital history. We aimed to assess the positive predictive value (PPV) of the diagnostic coding of anemia caused by bleeding in the DNRP.

Methods

In the DNRP, we identified all patients with International Classification of Disease, 10th edition codes for anemia caused by bleeding (acute: D50.0; chronic: D62.6) at three Danish hospitals from 2000 through 2009. For these patients we computed the PPV using hemoglobin level data, from Aarhus University laboratory database, as reference standard. Anemia was defined by a hemoglobin level less than 7.0 mmol/L for women and less than 8.0 mmol/L for men.

Results

We identified 3391 patients in the DNRP with a diagnosis of anemia caused by bleeding. The overall PPV was 95.4% (95% confidence interval [CI]: 94.6%–96.0%). The PPV was 97.6% (95% CI: 96.6%–98.3%) for men and 94.0% (95% CI: 92.9%–94.9%) for women, and the PPV increased with age at diagnosis. The PPV varied according to type of discharging departments, from 89.2% (95% CI: 83.4%–93.4%) in gynecology to 96.8% (95% CI: 94.9%–98.2%) in surgery, and was lower for outpatients compared with inpatients.

Conclusion

We found a high PPV of the coding for anemia caused by bleeding in the DNRP. The registry is a valid source of data on anemia caused by bleeding for various purposes including research and monitoring health care.

Validity of the diagnosis of acute myocardial infarction in korean national medical health insurance claims data: the korean heart study (1)

Background and Objectives

Medical insurance claims (MIC) data are one of the largest sources of outcome data in the form of International Classification of Diseases (ICD) codes. We evaluated the validity of the ICD codes from the Korean National MIC data with respect to the outcomes from acute myocardial infarction (AMI) in the Korean Heart Study.

Subjects and Methods

Baseline information was obtained from health examinations conducted from 1994 to 2001. Outcome information regarding the incidence of AMI came from hospital admission discharge records from 1994 to 2007. Structured questionnaires were sent to 98 hospitals. In total, 107 cases of AMI with ICD codes of I21- (93 men, 26-73 years of age) were included in the final analyses. ICD code accuracy and reliability (kappa) for AMI were calculated.

Results

A large number of AMI cases were from hospitals located in the Seoul area (75.9%). The accuracy of AMI was 71.4%, according to World Health Organization criteria (1997-2000, n=24, kappa=0.46) and 73.1% according to the European Society of Cardiology/American College of Cardiology (ESC/ACC) criteria (2001-2007, n=83, kappa=0.74). An age of 50 years or older was the only factor related to inaccuracy of codes for AMI (odds ratio, 4.6; 95% confidence interval, 1.2-17.7) in patients diagnosed since January 2001 using ESC/ACC criteria (n=83).

Conclusion

The accuracy for diagnosing AMI using the ICD-10 codes in Korean MIC data was >70%, and reliability was fair to good; however, more attention is required for recoding ICD codes in older patients.

Redefining syndromic surveillance

With growing concerns about international spread of disease and expanding use of early disease detection surveillance methods, the field of syndromic surveillance has received increased attention over the last decade. The purpose of this article is to clarify the various meanings that have been assigned to the term syndromic surveillance and to propose a refined categorization of the characteristics of these systems. Existing literature and conference proceedings were examined on syndromic surveillance from 1998 to 2010, focusing on low- and middle-income settings. Based on the 36 unique definitions of syndromic surveillance found in the literature, five commonly accepted principles of syndromic surveillance systems were identified, as well as two fundamental categories: specific and non-specific disease detection. Ultimately, the proposed categorization of syndromic surveillance distinguishes between systems that focus on detecting defined syndromes or outcomes of interest and those that aim to uncover non-specific trends that suggest an outbreak may be occurring. By providing an accurate and comprehensive picture of this field's capabilities, and differentiating among system types, a unified understanding of the syndromic surveillance field can be developed, encouraging the adoption, investment in, and implementation of these systems in settings that need bolstered surveillance capacity, particularly low- and middle-income countries.

Prescription audit of outpatient attendees of secondary level government hospitals in Maharashtra

OBJECTIVE

The main objective of the prescription audit of the secondary level government hospitals under the Maharashtra Health Systems Development Project (MHSDP) was to develop a list of essential drugs. Other objectives were to articulate measures for improving the prescription practices and to generate information on the core prescribing indicators proposed by the World Health Organization (WHO).

MATERIALS AND METHODS

The study was conducted among a representative sample of 31 secondary level hospitals under MHSDP. A copy of the prescription was obtained with the help of a pre-inserted carbon, in a special format. Data for only 'first encounter prescriptions' was collected for all patients attending the Outpatient Department (OPD).

RESULTS

About 77 percent of the prescriptions contained only one diagnosis. The average number of drugs per prescription was 3.1. About 60 percent of the drugs were prescribed by generic names and about 23 percent of the prescribed drugs were in combination. About 25 percent of the prescriptions contained at least one injection, while 35 percent contained at least one antibiotic. In 16 percent of the prescriptions a vitamin or tonic was prescribed. About 46 percent of the single ingredient formulations were as per the WHO 2003, Essential Medicines List (EML). Based on the findings of the Prescription Audit an EML was prepared for each category of the secondary level hospitals, for use in the OPD.

CONCLUSIONS

Prescription audits are useful in generating data on morbidity, which forms the basis for preparing the list of essential medicines. Mechanisms necessary for improving prescription practices are suggested.

A conceptual framework for the revision of the ICD-10 classification of mental and behavioural disorders

The World Health Organization (WHO) is revising the ICD-10 classification of mental and behavioural disorders, under the leadership of the Department of Mental Health and Substance Abuse and within the framework of the overall revision framework as directed by the World Health Assembly. This article describes WHO's perspective and priorities for mental and behavioural disorders classification in ICD-11, based on the recommendations of the International Advisory Group for the Revision of ICD-10 Mental and Behavioural Disorders. The WHO considers that the classification should be developed in consultation with stakeholders, which include WHO member countries, multidisciplinary health professionals, and users of mental health services and their families. Attention to the cultural framework must be a key element in defining future classification concepts. Uses of the ICD that must be considered include clinical applications, research, teaching and training, health statistics, and public health. The Advisory Group has determined that the current revision represents a particular opportunity to improve the classification's clinical utility, particularly in global primary care settings where there is the greatest opportunity to identify people who need mental health treatment. Based on WHO's mission and constitution, the usefulness of the classification in helping WHO member countries, particularly low- and middle-income countries, to reduce the disease burden associated with mental disorders is among the highest priorities for the revision. This article describes the foundation provided by the recommendations of the Advisory Group for the current phase of work.

The Concept of Somatisation: A Cross-cultural perspective

Somatisation is generally defined as the tendency to experience psychological distress in the form of somatic symptoms and to seek medical help for these symptoms, which may be initiated and/or perpetuated by emotional responses such as anxiety and depression. Somatisation has been recognised as a commonly encountered problem, especially in primary health care, contributing to frequent use of medical services and to frustration in both the patient and the doctor. In recent years, there has been a great deal of dissatisfaction with the terminology and classification of somatisation, and the way this definition is applied to non-Western cultures. This dilemma pertains to different aspects of the definitions, mainly their usefulness, adequacy and applicability. This article aims to review the literature on the development of the concept of somatisation and how this definition is applied from a cross-cultural aspect.

Aspects of Coding in Canada: Through the Eyes of an Australian HIM

For the purpose of this brief update report, the author (an Australian Health Information Manager currently working in Canada) was asked to select certain aspects of the current coding system in Canada that she believes highlight relevant differences between the Canadian and Australian systems, on the assumption that this might be of interest to other Australian HIMs. The author has provided a brief overview of some recent changes to the Canadian classification system (e.g. new electronic product replacing coding books), as well a focus on some aspects of coder training and coding studies as seen through the eyes of an Australian HIM.