Accuracy of Medicare claims-based diagnosis of acute myocardial infarction: estimating positive predictive value on the basis of review of hospital records

Background

Many cardiovascular epidemiologic studies rely on diagnosis codes in health care claims databases. Despite important changes in the care and diagnosis of acute myocardial infarction (AMI), the validity of hospital discharge diagnosis codes for AMI in the US Medicare system has not been recently examined. Our objective was to examine the accuracy of International Classification of Diseases—ninth revision—Clinical Modifications (ICD-9-CM) discharge diagnosis codes and diagnosis-related groups (DRG) codes for AMI in a Medicare claims database.

Methods

We sampled hospitalization episodes from Medicare beneficiaries in Pennsylvania during 1999, 2000, or both. We used Medicare data to identify patients with hospitalizations containing indicators of AMI (ICD-9-CM diagnosis codes 410.X0 and 410.X1 or DRG codes 121, 122, and 123). Hospital records for these episodes were reviewed by trained abstractors using World Health Organization criteria for diagnosing AMI. We then calculated the positive predictive value of Medicare claims-based definitions of AMI.

Results

Of 2200 hospitalization episodes with Medicare diagnosis codes suggestive of AMI, 2022 hospital records (91.9%) were obtained. The positive predictive value for a primary Medicare claims-based definition was 94.1% (95% CI, 93.0%-95.2%). Positive predictive values for alternative claims-based definitions ranged slightly, with the definition including DRG codes and length-of-stay restrictions yielding the highest positive predictive value, 95.4% (95% CI, 94.3%-96.4%). Subjects with a history of myocardial infarction had a significantly lower positive predictive value than subjects without a history of myocardial infarction (88.1% vs 94.6%, P <.001).

Conclusions

In this study, we observed high positive predictive values for a Medicare claims-based diagnosis of AMI and a diagnosis based on structured hospital record review.     

Nonalcoholic fatty liver disease in Japanese patients with severe obesity who received laparoscopic Roux-en-Y gastric bypass surgery (LRYGB) in comparison to non-Japanese patients

Background. The number of patients with morbid obesity is increasing worldwide. However, the prevalence of morbid obesity is still low in Japan, and therefore few systematic investigations of liver dysfunction in this population have so far been carried out. This study aimed to investigate the clinical characteristics in severe obese Japanese patients undergoing laparoscopic Roux-en-Y gastric bypass surgery (LRYGB). Methods. Eighty-four patients with severe obesity, including 61 Japanese and 23 non-Japanese patients, were analyzed. Results. The mean body mass index (BMI) was 43.7 ± 7.8 kg/m², and there was no difference between Japanese and non-Japanese patients. Nonalcoholic fatty liver disease (NAFLD) was observed in 45/59 (76.2%) of the Japanese patients. Although there were no differences in the BMI and body weight, serum ALT was higher in Japanese patients in comparison to non-Japanese patients (P < 0.05). The indices for insulin resistance were significantly higher in the Japanese patients in comparison to non-Japanese patients (P < 0.01). The liver/spleen computed tomography (CT) ratios were lower in Japanese patients (P < 0.05). The laboratory data and BMI significantly improved at 1 year after LRYGB in both groups. Conclusions. Racial difference may exist difference may exist in NAFLD in patients with severe obesity. When the BMI is similar, liver dysfunction among Japanese patients with severe obesity tends to be higher than in non-Japanese patients. Japanese patients with severe obesity must therefore reduce their body weight to a greater degree in comparison to non-Japanese patients with the same BMI. LRYGB can achieve effective weight control and lower ALT levels in Japanese patients with severe obesity.     

Coronary stent implantation in patients with a single coronary artery--a report of 3 cases

An isolated single coronary artery is a rare congenital anomaly and a cause of cardiac ischemia, congestive heart failure, and sudden cardiac death. Reported here are 3 cases of single coronary artery with acute myocardial infarction in which coronary stenting was performed. Also reported are the coronary blood flow patterns of the right coronary artery arising from the single left coronary artery.     

Infective endocarditis caused by lactobacillus

Lactobacillus (LB) is a gram-positive rod-shaped bacterium that inhabits the oral cavity, gastrointestinal tract, vagina and nasal cavity. Although LB plays a role in the prevention of infections caused by pathogenic bacteria, it causes some critical infectious diseases such as infective endocarditis (IE). IE due to LB is rare; however, early diagnosis and early treatment are important because of its high mortality rate. We report the onset of IE after otologic treatment in a heavy drinker of alcohol, the second case of IE due to LB in Japan.     

Combination Analysis in Genetic Polymorphisms of Drug-Metabolizing Enzymes CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A5 in the Japanese Population

The Cytochrome P450 is the major enzyme involved in drug metabolism. CYP enzymes are responsible for the metabolism of most clinically used drugs. Individual variability in CYP activity is one important factor that contributes to drug therapy failure. We have developed a new straightforward TaqMan PCR genotyping assay to investigate the prevalence of the most common allelic variants of polymorphic CYP enzymes CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A5 in the Japanese population. Moreover, we focused on the combination of each genotype for clinical treatment. The genotype analysis identified a total of 139 out of 483 genotype combinations of five genes in the 1,003 Japanese subjects. According to our results, most of subjects seemed to require dose modification during clinical treatment. In the near future, modifications should be considered based on the individual patient genotype of each treatment.     

Conditioned pain modulation in temporomandibular disorders (TMD) pain patients

The aims were to investigate (1) if temporomandibular disorders (TMD) patients with temporomandibular joint (TMJ) pain had different conditioned pain modulation (CPM) compared with healthy subjects and, (2) if clinical pain characteristics influenced CPM. Sixteen TMD pain patients and 16 age-matched healthy subjects were participated. A mechanical conditioning stimulus (CS) was applied to pericranial muscles provoking a pain intensity of 5/10 on a visual analogue scale. Pressure pain thresholds (PPT) and pressure pain tolerance thresholds (PPTol) were assessed at masseter, forearm and painful TMJ (only PPT) before, during, and 20 min after CS. Data were analyzed with ANOVAs. The correlations between CPM effect and ratings of TMD pain intensity on a numerical rating scale (NRS) or the pain duration were calculated (correlation coefficient; R). The relative PPT and PPTol increases (mean for the three assessment sites) during CS were significantly higher than baseline in healthy subjects (43.0 ± 3.6, 33.0 ± 4.0 %; P < 0.001, P < 0.001) but not in the TMD pain patients (4.9 ± 2.7, ?1.4 ± 4.1 %; P = 0.492, P = 1.000) with significant differences between groups (P < 0.001). In the patients, the relative PPT changes during CS were not significantly higher than baseline at TMJ (5.3 ± 3.8 %, P = 0.981) and masseter (?2.8 ± 4.8 %, P = 1.000) but significantly higher at forearm (12.3 ± 4.7 %, P = 0.039). No correlation was detected between TMD pain intensity and CPM effect (R = ?0.261; P = 0.337) or between pain duration and CPM effect (R = ?0.423; P = 0.103) at painful TMJ. These findings indicate that CPM is impaired in TMD pain patients especially at sites with chronic pain but not at pain-free sites and that the clinical pain characteristics do not influence CPM.     

A retrospective comparative study of mandibular fracture treatment with internal fixation using reconstruction plate versus miniplates

PurposeThis study compared the clinical success rates of mandibular fracture treatment using reconstruction plates or miniplates and clarified the selection criteria for reconstruction plates.MethodsAll patients who had surgically-treated mandible fractures from 2008 to 2017 with sufficient follow-up were retrospectively analyzed for information about the fracture condition, treatment, and outcomes.ResultsA total of 126 surgically-treated mandible fractures without mandibular condylar fracture in 105 patients (76 male, 29 female) were included. Reconstruction plates were used in 32 fractures with very good postoperative occlusal function. Four cases with complications requiring reoperation were treated using only miniplates. Variables that were statistically associated with follow-up surgery included simple versus comminuted mandible fracture, and the absence of teeth that could be used for intermaxillary fixation (P < 0.05). In the miniplates treatment for comminuted fracture, there was a significant difference in the treatment outcome depending on the number of free bone-fragments and the presence of bone-fragments requiring removal within 1 cm (P < 0.05).ConclusionReconstruction plates provided better treatment outcomes for comminuted fractures and fractures without teeth. Selecting a reconstruction plate that is capable of sufficiently overloading is important in comminuted fractures with multiple free bone-fragments and bone-fragments requiring removal.