Inpatient Codes Research Articles

Psychiatric Comorbidity and Mortality After Acute Myocardial Infarction

Prior studies of the impact of psychiatric comorbidity on outcomes after acute myocardial infarction (AMI) have frequently relied on inpatient secondary diagnosis codes. This study compared associations between psychiatric comorbidity and AMI outcomes that were derived using secondary diagnosis codes and codes captured from prior outpatient encounters. Retrospective cohort study analyzing 21 745 patients admitted in 2004 to 2006 to Veterans Health Administration hospitals with AMI using administrative data. Psychiatric comorbidity was identified using (1) secondary inpatient diagnosis codes from the index hospitalization and (2) diagnoses from prior outpatient encounters. Outcomes included 30- and 365-day mortality and the receipt of coronary revascularization within 30 days of admission. Generalized estimating equations and Cox proportional hazards were used to adjust mortality and receipt of revascularization for demographic and clinical variables. Psychiatric disorders were identified in 2285 (10%) patients from inpatient secondary diagnosis codes and 5225 (24%) patients from prior outpatient codes. Patients with psychiatric comorbidity had higher adjusted 30- and 365-day mortality, based on outpatient codes (odds ratios, 1.19 [95% CI, 1.09 to 1.30] and 1.12 [95% CI, 1.03 to 1.22], respectively), but similar mortality based on inpatient codes (odds ratios, 0.89 [95% CI, 0.69 to 1.01] and 0.93 [95% CI, 0.82 to 1.06], respectively). In contrast, patients with psychiatric comorbidity had lower receipt of coronary revascularization based on outpatient codes (hazard ratio, 0.92; [95% CI, 0.85 to 0.99], but similar receipt based on inpatient codes (hazard ratio, 1.00 [95% CI, 0.91 to 1.10]). Inpatient secondary diagnosis codes identified fewer patients with psychiatric comorbidity than prior outpatient codes. Moreover, associations with AMI outcomes differed for the 2 approaches. These findings raise potential concerns about the validity and reliability of psychiatric inpatient secondary diagnosis in estimating the impact of psychiatric comorbidities on AMI outcomes and in developing risk-adjustment models.

Diagnostic codes for sudden cardiac death and ventricular arrhythmia functioned poorly to identify outpatient events in EPIC's General Practice Research Database

To examine the validity of OXMIS/Read diagnoses of hospitalization for sudden cardiac death and ventricular arrhythmia (SD/VA) for use in studies of arrhythmogenic effects of outpatient medications in the General Practice Research Database (GPRD). We identified putative occurrences of hospitalization for SD/VA in patients receiving outpatient prescriptions for cisapride, domperidone, or metoclopramide. We then administered a questionnaire to general practitioners (GPs) caring for these patients, requested hospital discharge consult letters, and examined the positive predictive value (PPV) of diagnostic codes in identifying outpatient events precipitating hospitalization. We identified 84 putative events, 38 (45%) of which occurred in patients cared for by GPs participating in the follow-up scheme. Thirty of 38 questionnaires (79%) were completed. The PPV for the occurrence of any SD/VA was 93% (95% CI, 78-99%). However, the PPV for SD/VA occurrence in an outpatient setting precipitating a hospitalization was only 23% (95% CI, 10-42%). The majority of inpatient diagnostic codes reflected events occurring after hospital admission, not precipitating it. While computerized codes for SD/VA agreed well with physician diagnosis, they operated poorly to identify events occurring in an outpatient setting. Studies of SD/VA in the GPRD should verify events on a case-by-case basis.

Cost of Radiotherapy Versus NSAID Administration for Prevention of Heterotopic Ossification After Total Hip Arthroplasty

Heterotopic ossification (HO), or abnormal bone formation, is a common sequela of total hip arthroplasty. This abnormal bone can impair joint function and must be surgically removed to restore mobility. HO can be prevented by postoperative nonsteroidal anti-inflammatory drug (NSAID) use or radiotherapy (RT). NSAIDs are associated with multiple toxicities, including gastrointestinal bleeding. Although RT has been shown to be more efficacious than NSAIDs at preventing HO, its cost-effectiveness has been questioned. We performed an analysis of the cost of postoperative RT to the hip compared with NSAID administration, taking into account the costs of surgery for HO formation, treatment-induced morbidity, and productivity loss from missed work. The costs of RT, surgical revision, and treatment of gastrointestinal bleeding were estimated using the 2007 Medicare Fee Schedule and inpatient diagnosis-related group codes. The cost of lost wages was estimated using the 2006 median salary data from the U.S. Census Bureau. The cost of administering RT was estimated at $899 vs. $20 for NSAID use. After accounting for the additional costs associated with revision total hip arthroplasty and gastrointestinal bleeding, the corresponding estimated costs were $1,208 vs. $930. If the costs associated with treatment failure and treatment-induced morbidity are considered, the cost of NSAIDs approaches that of RT. Other NSAID morbidities and quality-of-life differences that are difficult to quantify add to the cost of NSAIDs. These considerations have led us to recommend RT as the preferred modality for use in prophylaxis against HO after total hip arthroplasty, even when the cost is considered.

Variations in the associations between psychiatric comorbidity and hospital mortality according to the method of identifying psychiatric diagnoses.

Little is known about associations between psychiatric comorbidity and hospital mortality for acute medical conditions. This study examined if associations varied according to the method of identifying psychiatric comorbidity and agreement between the different methods. The sample included 31,218 consecutive admissions to 168 Veterans Affairs facilities in 2004 with a principle diagnosis of congestive heart failure (CHF) or pneumonia. Psychiatric comorbidity was identified by: (1) secondary diagnosis codes from index admission, (2) prior outpatient diagnosis codes, (3) and prior mental health clinic visits. Generalized estimating equations (GEE) adjusted in-hospital mortality for demographics, comorbidity, and severity of illness, as measured by laboratory data. Rates of psychiatric comorbidities were 9.0% using inpatient diagnosis codes, 27.4% using outpatient diagnosis codes, and 31.0% using mental health visits for CHF and 14.5%, 33.1%, and 34.1%, respectively, for pneumonia. Agreement was highest for outpatient codes and mental health visits (kappa = 0.51 for pneumonia and 0.50 for CHF). In GEE analyses, the adjusted odds of death for patients with psychiatric comorbidity were lower when such comorbidity was identified by mental health visits for both pneumonia (odds ratio [OR] = 0.85; P = .009) and CHF (OR = 0.70; P < .001) and by inpatient diagnosis for pneumonia (OR = 0.63; P < or = .001) but not for CHF (OR = 0.75; P = .128). The odds of death were similar (P > .2) for psychiatric comorbidity as identified by outpatient codes for pneumonia (OR = 1.04) and CHF (OR = 0.93). The method used to identify psychiatric comorbidities in acute medical populations has a strong influence on the rates of identification and the associations between psychiatric illnesses with hospital mortality.

Predictive Value of ICD-9-CM Codes Used in Vaccine Safety Research

To assess how well selected ICD-9-CM diagnosis codes predict adverse events; to model bias and power loss when vaccine safety analyses rely on unverified codes. We extracted chart verification data for ICD-9-CM diagnosis codes from six Vaccine Safety Datalink (VSD) publications and modeled biases and power losses using positive predictive value (PPV) estimates and ranges of code sensitivity. Positive predictive values were high for type 1 diabetes (80%) in children, relative to WHO criteria, and intussusception (81%) in young children, relative to a standard published case definition. PPVs were moderate (65%) for inpatient and emergency department childhood seizures and low (21%) for outpatient childhood seizures, both relative to physician investigator judgment. Codes for incident central nervous system demyelinating disease in adults had high PPV for inpatient codes (80%) and low PPV for outpatient codes (42%) relative to physicians' diagnoses. Modeled biases were modest, but large increases in frequencies of adverse events are required to achieve adequate power if unverified ICD-9-CM codes are used, especially when vaccine associations are weak. ICD-9-CM codes for type 1 diabetes in children, intussusception in young children, childhood seizures in inpatient and emergency care settings, and inpatient demyelinating disease in adults were sufficiently predictive for vaccine safety analyses to rely on unverified diagnosis codes. Adverse event misclassification should be accounted for in statistical power calculations.

Cost-effectiveness of Radiation vs. NSAID Administration for Prevention of Heterotopic Ossification After Total Hip Arthroplasty

Purpose/Objective(s): Heterotopic ossification (HO), or abnomal bone formation, is a common sequela of total hip arthroplasty (THA). Often, this abnormal bone can impair joint function. Once formed, abnormal bone must be surgically removed to restore mobility. HO can be prevented by postoperative NSAID use or radiation to the periarticular tissues. NSAIDs are associated with multiple toxicities including gastritis, bleeding events and renal impairment. Although radiation has been shown to be more efficacious than NSAID administration in randomized trials and a meta-analysis, its cost-effectiveness has been questioned. Materials/Methods: We performed an analysis of the cost-effectiveness of single fraction post-operative radiation therapy to the hip as compared to NSAID administration, taking into account the added costs of surgery for failure of HO prophylaxis, treatment induced morbidity, and productivity loss from missed work. We used the preferred societal perspective. The direct medical costs of radiation, surgical revision for recurrent HO, and treatment of NSAID toxicity were estimated using the 2007 Medicare Fee Schedule and pricer software for 2007 Medicare inpatient DRG codes. The frequencies of these toxicities were taken from published randomized trials and the package insert for indomethacin. The indirect costs of lost wages were estimated using 2005 median salary data from the U.S. Census Bureau. Results: Conclusions: If one considers only the direct medical costs of treatment, then radiation appears to be much more expensive than NSAID administration for prevention of HO ($899 vs. $34). However, if one considers the additional costs associated with treatment failure and treatment induced morbidity, these costs converge ($1,207 vs. $991). This analysis is limited in that it did not attempt to assign a monetary value to the impairment in quality of life associated with symptomatic HO recurrence and the risk of death associated with GI hemorrhage (estimated at 5-10% of all patients admitted with NSAID induced GI bleeding). These considerations lead the authors to recommend radiation as the preferred modality for use in prophylaxis against HO after THA, even when cost-effectiveness is taken into consideration.

Hospital Discharge

Hospital Discharge

Unraveling the Puzzle: Critical Care, Intensive Care, or an Evaluation and Management Visit Code?

Unraveling the Puzzle: Critical Care, Intensive Care, or an Evaluation and Management Visit Code?

Development and Verification of a “Virtual” Cohort Using the National VA Health Information System

The VA's integrated electronic medical record makes it possible to create a "virtual" cohort of veterans with and without HIV infection to monitor trends in utilization, toxicity, and outcomes. We sought to develop a virtual cohort of HIV-infected veterans by adapting an existing algorithm, verifying this algorithm against independent clinical data, and finally identifying demographically-similar HIV-uninfected comparators. Subjects were identified from VA administrative data in fiscal years 1998-2003 using a modified existing algorithm, then linked with Immunology Case Registry (ICR, the VA's HIV registry) and Pharmacy Benefits Management (centralized database of outpatient prescriptions) to verify accuracy of identification. The algorithm was modified to maximize positive predictive value (PPV) against ICR. Finally, 2 HIV-uninfected comparators were matched to each HIV-infected subject. Using a single HIV code, 30,564 subjects were identified (positive predictive value 69%). Modification to require >1 outpatient or 1 inpatient code improved the positive predictive value to 88%. The lack of confirmatory laboratory and pharmacy data for the majority of subjects with a single outpatient code also supported this change. Of subjects identified with the modified algorithm, 89% had confirmatory evidence. When the modified algorithm was applied to fiscal years 1997-2004, 33,420 HIV-infected subjects were identified. Two HIV-uninfected comparators were matched to each subject for an overall cohort sample of 100,260. In the HAART era, HIV-related codes are sufficient for identifying HIV-infected subjects from administrative data when patients with a single outpatient code are excluded. A large cohort of HIV-infected subjects and matched comparators can be identified from existing VA administrative datasets.

Are Claims Data Accurate Enough to Identify Patients for Performance Measures or Quality Improvement? The Case of Diabetes, Heart Disease, and Depression

The objective of this study was to demonstrate a method to accurately identify patients with specific conditions from claims data for care improvement or performance measurement. In an iterative process of trial case definitions followed by review of repeated random samples of 10 to 20 cases for diabetes, heart disease, or newly treated depression, a final identification algorithm was created from claims files of health plan members. A final sample was used to calculate the positive predictive value (PPV). Each condition had unacceptably low PPVs (0.20, 0.60, and 0.65) when cases were identified on the basis of only 1 International Classification of Diseases, ninth revision, code per year. Requiring 2 outpatient codes or 1 inpatient code within 12 months (plus consideration of medication data for diabetes and extra criteria for depression) resulted in PPVs of 0.97, 0.95, and 0.95. This approach is feasible and necessary for those wanting to use administrative data for case identification for performance measurement or quality improvement.

Validation of administrative data used for the diagnosis of upper gastrointestinal events following nonsteroidal anti‐inflammatory drug prescription

To validate veterans affairs (VA) administrative data for the diagnosis of nonsteroidal anti-inflammatory drug (NSAID)-related upper gastrointestinal events (UGIE) and to develop a diagnostic algorithm. A retrospective study of veterans prescribed an NSAID as identified from the national pharmacy database merged with in-patient and out-patient data, followed by primary chart abstraction. Contingency tables were constructed to allow comparison with a random sample of patients prescribed an NSAID, but without UGIE. Multivariable logistic regression analysis was used to derive a predictive algorithm. Once derived, the algorithm was validated in a separate cohort of veterans. Of 906 patients, 606 had a diagnostic code for UGIE; 300 were a random subsample of 11 744 patients (control). Only 161 had a confirmed UGIE. The positive predictive value (PPV) of diagnostic codes was poor, but improved from 27% to 51% with the addition of endoscopic procedural codes. The strongest predictors of UGIE were an in-patient ICD-9 code for gastric ulcer, duodenal ulcer and haemorrhage combined with upper endoscopy. This algorithm had a PPV of 73% when limited to patients >or=65 years (c-statistic 0.79). Validation of the algorithm revealed a PPV of 80% among patients with an overlapping NSAID prescription. NSAID-related UGIE can be assessed using VA administrative data. The optimal algorithm includes an in-patient ICD-9 code for gastric or duodenal ulcer and gastrointestinal bleeding combined with a procedural code for upper endoscopy.

Consultation or Referral?

Current Procedural Terminology (CPT®) contains very specific guidelines on reporting consultations. A consultation is defined as a service that is provided by a physician when another physician or other appropriate source requests the consulting physician’s opinion or advice concerning the evaluation and/or management of a specific problem.Given that definition, how does CPT define “other appropriate source”?The guidelines do not specify or restrict who may be considered an “other appropriate source.” Examples of appropriate sources are a school nurse; physician extender; physical, speech, or occupational therapist; insurance company; and lawyer. It is important to note that the patient and family are not considered appropriate sources.Tip: If an insurance company mandates the consultation, modifier -32, mandated services, should be appended to the consultation code.The requirements are known as the 3 Rs.The consulting physician can initiate diagnostic or therapeutic services during the visit or subsequent visits. Procedures would be reported separately from the consultation. The consulting physician can take over the care of the patient or provide management of a particular problem (eg, diabetes, hypertension) when noted in the requesting or attending physician’s documentation. Remember, the follow-up inpatient consultation codes (99261–99263) have been deleted (this is new in 2006). Therefore, any subsequent inpatient care provided by the consultant is reported using subsequent hospital visit codes (99231–99233), established patient office visit codes (99211–99215), or nursing home visit codes (99311– 99313), depending on the site of service.Tip: CPT recognizes the term referralas a transfer of care. If you use the word referral, do not report a consultation unless you meet all the criteria as noted previously. Appropriate documentation for a referral would be, “Mrs X referred by Dr Y for opinion on [topic].” The terms referral and consultation are not interchangeable.Don’t confuse counseling or referrals for transfer of care with consultations! Just use the 3 Rs as your guide and you will be coding appropriately.

Intussusception Incidence Relative to Rotavirus Vaccine Use in Honolulu

Rotavirus vaccine was in use during the period August 1998 to October 1999. Epidemics of intussusception during this period were allegedly due to rotavirus vaccine, which prompted the vaccine to be withdrawn. Hawaii's geographic location between Asia and the mainland United States may subject it to infectious disease epidemic periods midway between occurrence in Asia and occurrence in the mainland United States. In contrast, immunization recommendations are temporally identical across all 50 states. The purpose of this study was to determine whether an epidemic of intussusception was experienced in Honolulu during the period of rotavirus vaccine use. This is a retrospective study of data obtained from inpatient and emergency department discharge diagnosis codes of intussusception for children up to 36 months of age. The incidence data were plotted by time periods to identify possible epidemic periods. The data are graphed. The arrows on the graphs indicate the period of time that rotavirus vaccine was in use. These graphs are most consistent with an increase in the cases of intussusception during the period July 2000 to December 2000, and a possible decline of intussusception during the rotavirus vaccine period. These incidence data are inconsistent with a temporal association between rotavirus vaccine and an epidemic of intussusception in Honolulu.

ICD-9-CM and CPT Codes for 2006

<i>ICD-9-CM</i> and <i>CPT</i> Codes for 2006

Measuring Diagnoses: ICD Code Accuracy

To examine potential sources of errors at each step of the described inpatient International Classification of Diseases (ICD) coding process. The use of disease codes from the ICD has expanded from classifying morbidity and mortality information for statistical purposes to diverse sets of applications in research, health care policy, and health care finance. By describing a brief history of ICD coding, detailing the process for assigning codes, identifying where errors can be introduced into the process, and reviewing methods for examining code accuracy, we help code users more systematically evaluate code accuracy for their particular applications. We summarize the inpatient ICD diagnostic coding process from patient admission to diagnostic code assignment. We examine potential sources of errors at each step and offer code users a tool for systematically evaluating code accuracy. Main error sources along the "patient trajectory" include amount and quality of information at admission, communication among patients and providers, the clinician's knowledge and experience with the illness, and the clinician's attention to detail. Main error sources along the "paper trail" include variance in the electronic and written records, coder training and experience, facility quality-control efforts, and unintentional and intentional coder errors, such as misspecification, unbundling, and upcoding. By clearly specifying the code assignment process and heightening their awareness of potential error sources, code users can better evaluate the applicability and limitations of codes for their particular situations. ICD codes can then be used in the most appropriate ways.

New 2005 CPT Codes

New 2005 <i>CPT</i> Codes

Intussusception incidence relative to rotavirus vaccine use in Honolulu

Study objectives: Rotavirus vaccine was in use during August 1998 to October 1999. Epidemics of intussusception during this period were allegedly caused by rotavirus vaccine, which prompted the vaccine to be withdrawn. Hawaii's geographic location between Asia and the mainland United States may subject it to infectious disease epidemic periods midway between occurrence in Asia and occurrence in the mainland United States. In contrast, immunization recommendations are temporally identical across all 50 states. The purpose of this study is to determine whether an epidemic of intussusception was experienced in Honolulu during the period of Rotavirus vaccine use. Methods: This is a retrospective study of data obtained from inpatient and emergency department discharge diagnosis codes of intussusception for children up to 36 months of age. The incidence data were plotted by time periods to identify possible epidemic periods. Results: Among those younger than 36 months old, the incidence of intussusception (in 4-month blocks) during the rotavirus vaccine use period was 4, 4, 2, 4 and 2 cases during each of the 4-month blocks beginning July 1998 and ending December 1999. This compares to an incidence of 2 to 4 cases per 4-month block before the rotavirus vaccine period from May 1994 to June 1998. From January 2000, the incidence per 4-month block has been 4, 4, 6, 6, 5, 4, 6, 4, 5, 4, 4, and 1. This suggests a small epidemic of intussusception cases well after the period of rotavirus vaccine use. Conclusion: These incidence data are inconsistent with the allegation that rotavirus vaccine caused an epidemic of intussusception in Honolulu.

Payer status is related to differences in access and outcomes of abdominal aortic aneurysm repair in the United States: Boxter LK, Dimick JB, Wainess RM, et al. Surgery 2003;134L:142-5

ConclusionThere were greater operative mortality rates in uninsured patients for both elective and emergent abdominal aortic aneurysm (AAA) repair. Uninsured patients underwent treatment for ruptured AAAs more often than did patients with private insurance. SummaryThe authors studied whether patients with private insurance, compared with patients with Medicaid or no insurance, differ with respect to outcome of AAA repair and timely access to treatment of AAA.The national inpatient procedure diagnostic codes for AAA repair, intact and ruptured, were examined for 5363 patients younger than 65 years, from 1995 to 2000, with risk-adjusted analyses for access to AAA treatment and outcomes of repair. Dependent variables included in-hospital mortality, ruptured AAA, and intact AAA. Independent variables were comorbid disease, gender, age, race, payer status, and median income.Patients with no insurance or Medicaid were more likely to have AAA rupture (P < .001). Patients without insurance were at increased risk for rupture compared with patients with private insurance (odds ratio, 2.3; 95% confidence interval, 1.5-3.5; P < .001). Operative mortality rates appeared greater after elective AAA repair in patients with no insurance or Medicaid compared with patients with private insurance. Operative mortality rates were also higher after ruptured AAA repair in patients without insurance or Medicaid. CommentAdditional analyses are needed to determine whether patients without insurance or with Medicaid tend to avoid health care because of the financial burden or whether delayed access to surgical treatment results from gate-keeping issues or other deterrents to health care among patients with no insurance or Medicaid.

Hospital Consultations: Expert Evaluations—Expert Coding!

Hospital Consultations: Expert Evaluations—Expert Coding!

Overview of inpatient coding

The main classification-based and nomenclature-based coding systems used in the United States, as well as the process and importance of documenting in the patient record, are discussed. Hospital pharmacists usually have limited knowledge of and exposure to coding and reimbursement in the inpatient system. Coding allows for reporting of mortality data to the World Health Organization (WHO), reporting morbidity data in the U.S., and providing data for reimbursement from third-party payers to hospitals for services provided. Coded information is also the primary source for administrative management of medical services and a source of epidemiologic and statistical data from inpatient stays. In order to better understand inpatient coding and reimbursement, this article will discuss the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) coding system; the Healthcare Common Procedure Coding System (HCPCS); the process and importance of appropriate chart documentation; and the development of the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) coding system. Coding in the inpatient setting enables hospital billing and provides statistical data for epidemiology and financial planning. The ICD-9-CM is a clinically modified version of the international ICD-9 system used for coding both diagnoses and procedures in the United States. Coding is derived from documentation found in the patient's chart. Appropriate documentation is key for quality and continuity of care and compensation for resources utilized. In the future the ICD-9-CM will be replaced by the 10th revision, ICD-10, which is already in use in many countries in Europe.