Bronchiectasis as a Comorbidity of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Background

Bronchiectasis revealed by chest computed tomography in COPD patients and its comorbid effect on prognosis have not been addressed by large-sized studies. Understanding the presence of bronchiectasis in COPD is important for future intervention and preventing disease progression.

Methods

Observational studies were identified from electronic literature searches in Cochrane library, PubMed, ScienceDirect databases, American Thoracic Society and European Respiratory Society meeting abstracts. A systematic review and meta-analysis of studies was performed to summarize the factors associated with bronchiectasis in COPD patients. Primary outcomes included the risks for exacerbation frequency, isolation of a potentially pathogenic microorganism, severe airway obstruction and mortality. Odds ratios (ORs) were pooled by random effects models.

Results

Fourteen observational studies were eligible for the study. Compared with COPD without bronchiectasis, comorbid bronchiectasis in COPD increased the risk of exacerbation (1.97, 95% CI, 1.29–3.00), isolation of a potentially pathogenic microorganism (4.11, 95%CI, 2.16–7.82), severe airway obstruction (1.31, 95% CI, 1.09–1.58) and mortality (1.96, 95% CI, 1.04–3.70).

Conclusions

The presence of bronchiectasis in patients with COPD was associated with exacerbation frequency, isolation of a potentially pathogenic microorganism, severe airway obstruction and mortality.     

The Effect of Comorbidity on Glycemic Control and Systolic Blood Pressure in Type 2 Diabetes: A Cohort Study with 5 Year Follow-Up in Primary Care

Aims

To explore the longitudinal effect of chronic comorbid diseases on glycemic control (HbA₁C) and systolic blood pressure (SBP) in type 2 diabetes patients.

Methods

In a representative primary care cohort of patients with newly diagnosed type 2 diabetes in The Netherlands (n = 610), we tested differences in the five year trend of HbA₁C and SBP according to comorbidity profiles. In a mixed model analysis technique we corrected for relevant covariates. Influence of comorbidity (a chronic disease already present when diabetes was diagnosed) was tested as total number of comorbid diseases, and as presence of specific disease groups, i.e. cardiovascular, mental, and musculoskeletal disease, malignancies, and COPD. In subgroup effect analyses we tested if potential differences were modified by age, sex, socioeconomic status, and BMI.

Results

The number of comorbid diseases significantly influenced the SBP trend, with highest values after five years for diabetes patients without comorbidity (p = 0.005). The number of diseases did not influence the HbA₁C trend (p = 0.075). Comorbid musculoskeletal disease resulted in lower HbA₁C at the time of diabetes diagnosis, but in higher values after five years (p = 0.044). Patients with cardiovascular diseases had sustained elevated levels of SBP (p = 0.014). Effect modification by socioeconomic status was observed in some comorbidity subgroups.

Conclusions

Presence of comorbidity in type 2 diabetes patients affected the long-term course of HbA₁C and SBP in this primary care cohort. Numbers and types of comorbidity showed differential effects: not the simple sum of diseases, but specific types of comorbid disease had a negative influence on long-term diabetes control parameters. The complex interactions between comorbidity, diabetes control and effect modifiers require further investigation and may help to personalize treatment goals.     

Direct Healthcare Cost of Obesity in Brazil: An Application of the Cost-of-Illness Method from the Perspective of the Public Health System in 2011

Background

Obesity is a global public health problem and a risk factor for several diseases that financially impact healthcare systems.

Objective

To estimate the direct costs attributable to obesity (body mass index {BMI} ≥ 30 kg/m²) and morbid obesity (BMI ≥ 40 kg/m²) in adults aged ≥ 20 incurred by the Brazilian public health system in 2011.

Settings

Public hospitals and outpatient care.

Methods

A cost-of-illness method was adopted using a top-down approach based on prevalence. The proportion of the cost of each obesity-associated comorbidity was calculated and obesity prevalence was used to calculate attributable risk. Direct healthcare cost data (inpatient care, bariatric surgery, outpatient care, medications and diagnostic procedures) were extracted from the Ministry of Health information systems, available on the web.

Results

Direct costs attributable to obesity totaled US$ 269.6 million (1.86% of all expenditures on medium- and high-complexity health care). The cost of morbid obesity accounted for 23.8% (US$ 64.2 million) of all obesity-related costs despite being 18 times less prevalent than obesity. Bariatric surgery costs in Brazil totaled US$ 17.4 million in 2011. The cost of morbid obesity in women was five times higher than it was in men.

Conclusion

The cost of morbid obesity was found to be proportionally higher than the cost of obesity. If the current epidemic were not reversed, the prevalence of obesity in Brazil will increase gradually in the coming years, as well as its costs, having serious implications for the financial sustainability of the Brazilian public health system.     

Comorbid Diseases Interact with Breast Cancer to Affect Mortality in the First Year after Diagnosis—A Danish Nationwide Matched Cohort Study

Background

Survival of breast cancer patients with comorbidity, compared to those without comorbidity, has been well characterized. The interaction between comorbid diseases and breast cancer, however, has not been well-studied.

Methods

From Danish nationwide medical registries, we identified all breast cancer patients between 45 and 85 years of age diagnosed from 1994 to 2008. Women without breast cancer were matched to the breast cancer patients on specific comorbid diseases included in the Charlson comorbidity Index (CCI). Interaction contrasts were calculated as a measure of synergistic effect on mortality between comorbidity and breast cancer.

Results

The study included 47,904 breast cancer patients and 237,938 matched comparison women. In the first year, the strongest interaction between comorbidity and breast cancer was observed in breast cancer patients with a CCI score of ≥4, which accounted for 29 deaths per 1000 person-years. Among individual comorbidities, dementia interacted strongly with breast cancer and accounted for 148 deaths per 1000 person-years within one year of follow-up. There was little interaction between comorbidity and breast cancer during one to five years of follow-up.

Conclusions

There was substantial interaction between comorbid diseases and breast cancer, affecting mortality. Successful treatment of the comorbid diseases or the breast cancer can delay mortality caused by this interaction in breast cancer patients.     

Socio-Economic and Clinical Factors as Predictors of Disease Evolution and Acute Events in COPD Patients

Background

Socio-economic, cultural and environmental factors are becoming increasingly important determinants of chronic obstructive pulmonary disease (COPD). We conducted a study to investigate socio-demographic, lifestyle and clinical factors, and to assess their role as predictors of acute events (mortality or hospitalization for respiratory causes) in a group of COPD patients.

Methods

Subjects were recruited among outpatients who were undertaking respiratory function tests at the Pneumology Unit of the Sant’Orsola-Malpighi Hospital, Bologna. Patients were classified according to the GOLD Guidelines.

Results

229 patients with COPD were included in the study, 44 with Mild, 68 Moderate, 52 Severe and 65 Very Severe COPD (GOLD stage). Significant differences among COPD stage, in terms of smoking status and fragility index, were detected. COPD stage significantly affected the values of all clinical tests (spirometry and ABG analysis). Kaplan-Meier estimates showed a significant difference between survival curves by COPD stage with lower event-free probability in very severe COPD stage. Significant risk factors for acute events were: underweight (HR = 4.08; 95% CI 1.01–16.54), having two or more comorbidities (HR = 4.71; 95% CI 2.52–8.83), belonging to moderate (HR = 3.50; 95% CI 1.01–12.18) or very severe COPD stage (HR = 8.23; 95% CI 2.35–28.85).

Conclusions

Our findings indicate that fragility is associated with COPD stage and that comorbidities and the low body mass index are predictors of mortality or hospitalization. Besides spirometric analyses, FeNO measure and comorbidities, body mass index could also be considered in the management and monitoring of COPD patients.     

Validity of the Age-Adjusted Charlson Comorbidity Index on Clinical Outcomes for Patients with Nasopharyngeal Cancer Post Radiation Treatment: A 5-Year Nationwide Cohort Study

Purpose

To characterize the impact of comorbidity on survival outcomes for patients with nasopharyngeal carcinoma (NPC) post radiotherapy (RT).

Methods

A total of 4095 patients with NPC treated by RT or RT plus chemotherapy (CT) in the period from 2007 to 2011 were included through Taiwan’s National Health Insurance Research Database. Information on comorbidity present prior to the NPC diagnosis was obtained and adapted to the Charlson Comorbidity Index (CCI), Age-Adjusted Charlson Comorbidity Index (ACCI) and a revised head and neck comorbidity index (HN-CCI). The prevalence of comorbidity and the influence on survival were calculated and analyzed.

Results

Most of the patients (75%) were male (age 51±13 years) and 2470 of them (60%) had at least one comorbid condition. The most common comorbid condition was diabetes mellitus. According to these three different comorbidity index (CCI, ACCI and HN-CCI), higher scores were associated with worse overall survival (P< 0.001). The Receiver Operating Characteristic (ROC) curve was used to assess the discriminating ability of CCI, AACI and HN-CCI scores and it demonstrated the predictive ability for mortality with the ACCI (0.693, 95% CI 0.670–0.715) was superior to that of the CCI (0.619, 95% CI 0.593–0.644) and HN-CCI (0.545, 95%CI 0.519–0.570).

Conclusion

Comorbidities greatly influenced the clinical presentations, therapeutic interventions, and outcomes of patients with NPC post RT. Higher comorbidity index scores accurately was associated with worse survival. The ACCI seems to be a more appropriate prognostic indicator and should be considered in further clinical studies.     

Determinants of per diem Hospital Costs in Mental Health

Introduction

An understanding of differences in hospital costs between patient groups is relevant for the efficient organisation of inpatient care. The main aim of this study was to confirm the hypothesis that eight a priori identified cost drivers influence per diem hospital costs. A second aim was to explore further variables that might influence hospital costs.

Methods

The study included 667 inpatient episodes consecutively discharged in 2014 at the psychiatric hospital of the Medical Centre- University of Freiburg. Fifty-one patient characteristics were analysed. Per diem costs were calculated from the hospital perspective based on a detailed documentation of resource use. Mixed-effects maximum likelihood regression and an ensemble of conditional inference trees were used to analyse data.

Results

The study confirmed the a priori hypothesis that not being of middle age (33–64 years), danger to self, involuntary admission, problems in the activities of daily living, the presence of delusional symptoms, the presence of affective symptoms, short length of stay and the discharging ward affect per diem hospital costs. A patient classification system for prospective per diem payment was suggested with the highest per diem hospital costs in episodes having both delusional symptoms and involuntary admissions and the lowest hospital costs in episodes having neither delusional symptoms nor somatic comorbidities.

Conclusion

Although reliable cost drivers were identified, idiosyncrasies of mental health care complicated the identification of clear and consistent differences in hospital costs between patient groups. Further research could greatly inform current discussions about inpatient mental health reimbursement, in particular with multicentre studies that might find algorithms to split patients in more resource-homogeneous groups.     

Oxygen Therapy Use in Older Adults with Chronic Obstructive Pulmonary Disease

Rationale

Oxygen therapy improves survival and function in severely hypoxemic chronic obstructive pulmonary disease (COPD) patients based on two landmark studies conducted over 40 years ago. We hypothesize that oxygen users in the current era may be very different. We examined trends and subject characteristics associated with oxygen therapy use from 2001–2010 in the United States.

Methods

We examined Medicare beneficiaries with COPD who received oxygen from 2001 to 2010. COPD subjects were identified by: 1) ≥2 outpatient visits >30 days apart within one year with an encounter diagnosis of COPD; or 2) an acute care hospitalization with COPD as the primary or secondary discharge diagnosis. Oxygen therapy and sustained oxygen therapy were defined as ≥1 and ≥11 claims for oxygen, respectively, in the durable medical equipment file in a calendar year. Primary outcome measures were factors associated with oxygen therapy and sustained oxygen therapy over the study period.

Results

Oxygen therapy increased from 33.7% in 2001 to 40.5% in 2010 (p-value of trend <0.001). Sustained oxygen therapy use increased from 19.5% in 2001, peaked in 2008 to 26.9% and declined to 18.5% in 2010. The majority of subjects receiving oxygen therapy and sustained oxygen therapy were female. Besides gender, factors associated with any oxygen use or sustained oxygen therapy were non-Hispanic white race, low socioeconomic status and ≥2 comorbidities.

Conclusions

Any oxygen use among fee-for service Medicare beneficiaries with COPD is high. Current users of oxygen are older females with multiple comorbidities. Decline in sustained oxygen therapy use after 2008 may be related to reimbursement policy change.     

Comparison of Outcomes and Costs of Ranibizumab and Aflibercept Treatment in Real-Life

Background

Treatment efficacy and costs of anti-VEGF drugs have not been studied in clinical routine.

Objective

To compare treatment costs and clinical outcomes of the medications when adjusting for patients’ characteristics and clinical status.

Design

Comparative study.

Setting

The largest public ophthalmologic clinic in Switzerland.

Patients

Health care claims data of patients with age-related macular degeneration, diabetic macula edema and retinal vein occlusion were matched to clinical and outcome data.

Measurements

Patients’ underlying condition, gender, age, visual acuity and retinal thickness at baseline and after completing the loading phase, the total number of injections per treatment, the visual outcome and vital status was secured.

Results

We included 315 patients (19595 claims) with a follow-up time of 1 to 99 months (mean 32.7, SD 25.8) covering the years 2006–2014. Mean age was 78 years (SD 9.3) and 200 (63.5%) were female. At baseline, the mean number of letters was 55.6 (SD 16.3) and the central retinal thickness was 400.1 μm (SD 110.1). Patients received a mean number of 15.1 injections (SD 13.7; range 1 to 85). Compared to AMD, adjusted cost per month were significantly higher (+2174.88 CHF, 95%CI: 1094.50–3255.27; p<0.001) for patients with DME, while cost per month for RVO were slightly but not significantly higher. (+284.71 CHF, 95% CI: -866.73–1436.15; p = 0.627).

Conclusions

Patients with DME are almost twice as expensive as AMD and RVO patients. Cost excess occurs with non-ophthalmologic interventions. The currently licensed anti-VEGF medications did not differ in costs, injection frequency and clinical outcomes. Linking health care claims to clinical data is a useful tool to examine routine clinical care.     

Asthma and COPD Overlap Syndrome (ACOS): A Systematic Review and Meta Analysis

Background

The combination of asthma and chronic obstructive pulmonary disease (COPD), or ACOS is a recently defined syndrome. The epidemiology of the condition is poorly described and previous research has suggested ACOS is associated with worse outcomes than either condition alone. We therefore decided to complete a systematic review of the published literature.

Methods

This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta- Analyses guidelines. A structured search was performed in the PubMed, Embase, and Medline databases up to Feb 2015 to identify studies reporting incidence, prevalence, health care utilization, morbidity, or mortality in COPD and asthma.

Results

A total of 19 studies were included in the present study. The pooled prevalence of overlap among COPD was 27% (95% CI: 0.16–0.38, p<0.0001) and 28% (95% CI: 0.09–0.47, p = 0.0032) in the population and hospital-based studies, respectively. We found no significant difference between ACOS and COPD in terms of gender, smoking status, lung function and 6mWD. However, in comparison to subject with only COPD, ACOS subjects were significantly younger, had higher BMI, healthcare utilization, and lower HRQoL.

Conclusion

ACOS is a common condition that exists in a substantial proportion of subjects with COPD. ACOS represents a distinct clinical phenotype with more frequent exacerbations, hospitalization, worse health-related quality of life, and higher healthcare costs than either disease alone. There is a critical need to better define the management and treatment of this syndrome.     

Utilities of Patients with Hypertension in Northern Vietnam

Objectives

The study aims to inform potential cost-effectiveness analysis of hypertension management in Vietnam by providing utilities and predictors of utilities in patients with hypertension.

Methods

Hypertensive patients up to 80 years old visiting the hospital were invited to participate in a survey using Quality Metric’s Short-form 36v2^TM translated into Vietnamese. Health-state utilities were estimated by applying a previously published algorithm.

Results

The mean utility of the 691 patients interviewed was 0.73. Controlling for age, sex, blood pressure (BP) stage, and history of stroke, the utilities in older patients were lower than those in younger ones, and statistically significantly different between the extremes of youngest and oldest groups (p = 0.03). Utility in males was higher than in females (p = 0.002). As expected, patients with a history of stroke appeared to exhibit lower utilities than patients without such history, but the difference was not statistically significant (p = 0.73). Patients with more than three comorbidities did have lower utilities than patients without comorbidity (p = 0.01).

Conclusions

Health-state utilities found among hypertensive patients in Vietnam were similar to those found in other international studies. It is suggested that lower of health-state utilities exist among those patients who were older, female or had more than three comorbidities in comparison with respective reference groups. However, further research for confirmation is required. The data from this study provide a potential reference on health-state utilities of hypertensive patients in Vietnam as an input for future cost-effectiveness analysis of interventions. Also, it may serve as a reference for other similar populations, especially in the context of similar environments in low income countries.     

Incidence and Cost of Pneumonia in Older Adults with COPD in the United States

Objectives

To estimate the incidence of pneumonia by COPD status and the excess cost of inpatient primary pneumonia in elders with COPD.

Study Design

A retrospective, longitudinal study using claims linked to eligibility/demographic data for a 5% sample of fee-for-service Medicare beneficiaries from 2005 through 2007.

Methods

Incidence rates of pneumonia were calculated for elders with and without COPD and for elders with COPD and coexistent congestive heart failure (CHF). Propensity-score matching with multivariate generalized linear regression was used to estimate the excess direct medical cost of inpatient primary pneumonia in elders with COPD as compared with elders with COPD but without a pneumonia hospitalization.

Results

Elders with COPD had nearly six-times the incidence of pneumonia compared with elders without COPD (167.6/1000 person-years versus 29.5/1000 person-years; RR=5.7, p <0 .01); RR increased to 8.1 for elders with COPD and CHF compared with elders without COPD. The incidence of inpatient primary pneumonia among elders with COPD was 54.2/1000 person-years compared with 7/1000 person-years for elders without COPD; RR=7.7, p<0.01); RR increased to 11.0 for elders with COPD and CHF compared with elders without COPD. The one-year excess direct medical cost of inpatient pneumonia in COPD patients was $ 22,697 ($45,456 in cases vs. $ 22,759 in controls (p <0.01)); 70.2% of this cost was accrued during the quarter of the index hospitalization. During months 13 through 24 following the index hospitalization, the excess direct medical cost was $ 5,941 ($23,215 in cases vs. $ 17,274 in controls, p<0.01).

Conclusions

Pneumonia occurs more frequently in elders with COPD than without COPD. The excess direct medical cost in elders with inpatient pneumonia extends up to 24 months following the index hospitalization and represents $28,638 in 2010 dollars.     

The Joint Effects of Lifestyle Factors and Comorbidities on the Risk of Colorectal Cancer: A Large Chinese Retrospective Case-Control Study

Background

Colorectal cancer (CRC) is a major cause of cancer morbidity and mortality. In previous epidemiologic studies, the respective correlation between lifestyle factors and comorbidity and CRC has been extensively studied. However, little is known about their joint effects on CRC.

Methods

We conducted a retrospective case-control study of 1,144 diagnosed CRC patients and 60,549 community controls. A structured questionnaire was administered to the participants about their socio-demographic factors, anthropometric measures, comorbidity history and lifestyle factors. Logistic regression model was used to calculate the odds ratio (ORs) and 95% confidence intervals (95%CIs) for each factor. According to the results from logistic regression model, we further developed healthy lifestyle index (HLI) and comorbidity history index (CHI) to investigate their independent and joint effects on CRC risk.

Results

Four lifestyle factors (including physical activities, sleep, red meat and vegetable consumption) and four types of comorbidity (including diabetes, hyperlipidemia, history of inflammatory bowel disease and polyps) were found to be independently associated with the risk of CRC in multivariant logistic regression model. Intriguingly, their combined pattern- HLI and CHI demonstrated significant correlation with CRC risk independently (OR_HLI: 3.91, 95%CI: 3.13–4.88; OR_CHI: 2.49, 95%CI: 2.11–2.93) and jointly (OR: 10.33, 95%CI: 6.59–16.18).

Conclusions

There are synergistic effects of lifestyle factors and comorbidity on the risk of colorectal cancer in the Chinese population.     

Costing Alternative Birth Settings for Women at Low Risk of Complications: A Systematic Review

Background

There is demand from women for alternatives to giving birth in a standard hospital setting however access to these services is limited. This systematic review examines the literature relating to the economic evaluations of birth setting for women at low risk of complications.

Methods

Searches of the literature to identify economic evaluations of different birth settings of the following electronic databases: MEDLINE, CINAHL, EconLit, Business Source Complete and Maternity and Infant care. Relevant English language publications were chosen using keywords and MeSH terms between 1995 and 2015. Inclusion criteria included studies focussing on the comparison of birth setting. Data were extracted with respect to study design, perspective, PICO principles, and resource use and cost data.

Results

Eleven studies were included from Australia, Canada, the Netherlands, Norway, the USA, and the UK. Four studies compared costs between homebirth and the hospital setting and the remaining seven focussed on the cost of birth centre care and the hospital setting. Six studies used a cost-effectiveness analysis and the remaining five studies used cost analysis and cost comparison methods. Eight of the 11 studies found a cost saving in the alternative settings. Two found no difference in the cost of the alternative settings and one found an increase in birth centre care.

Conclusions

There are few studies that compare the cost of birth setting. The variation in the results may be attributable to the cost data collection processes, difference in health systems and differences in which costs were included. A better understanding of the cost of birth setting is needed to inform policy makers and service providers.     

Economic Impact of Dementia by Disease Severity: Exploring the Relationship between Stage of Dementia and Cost of Care in Taiwan

Objective

Given the shortage of cost-of-illness studies in dementia outside of the Western population, the current study estimated the annual cost of dementia in Taiwan and assessed whether different categories of care costs vary by severity using multiple disease-severity measures.

Methods

This study included 231 dementia patient–caregiver dyads in a dementia clinic at a national university hospital in southern Taiwan. Three disease measures including cognitive, functional, and behavioral disturbances were obtained from patients based on medical history. A societal perspective was used to estimate the total costs of dementia according to three cost sub-categories. The association between dementia severity and cost of care was examined through bivariate and multivariate analyses.

Results

Total costs of care for moderate dementia patient were 1.4 times the costs for mild dementia and doubled from mild to severe dementia among our community-dwelling dementia sample. Multivariate analysis indicated that functional declines had a greater impact on all cost outcomes as compared to behavioral disturbance, which showed no impact on any costs. Informal care costs accounted for the greatest share in total cost of care for both mild (42%) and severe (43%) dementia patients.

Conclusions

Since the total costs of dementia increased with severity, providing care to delay disease progression, with a focus on maintaining patient physical function, may reduce the overall cost of dementia. The greater contribution of informal care to total costs as opposed to social care also suggests a need for more publicly-funded long-term care services to assist family caregivers of dementia patients in Taiwan.     

The Charlson Comorbidity Index Can Be Used Prospectively to Identify Patients Who Will Incur High Future Costs

Background

Reducing health care costs requires the ability to identify patients most likely to incur high costs. Our objective was to evaluate the ability of the Charlson comorbidity score to predict the individuals who would incur high costs in the subsequent year and to contrast its predictive ability with other commonly used predictors.

Methods

We contrasted the prior year Charlson comorbidity index, costs, Diagnostic Cost Group (DCG) and hospitalization as predictors of subsequent year costs from claims data of fund that provides comprehensive health benefits to a large union of health care workers. Total costs in the subsequent year was the principal outcome.

Results

Of the 181,764 predominantly Black and Latino beneficiaries, 70% were adults (mean age 45.7 years; 62% women). As the comorbidity index increased, total yearly costs increased significantly (P<.001). At lower comorbidity, the costs were similar across different chronic diseases. Using regression to predict total costs, top 5^th and 10^th percentile of costs, the comorbidity index, prior costs and DCG achieved almost identical explained variance in both adults and children.

Conclusions and Relevance

The comorbidity index predicted health costs in the subsequent year, performing as well as prior cost and DCG in identifying those in the top 5% or 10%. The comorbidity index can be used prospectively to identify patients who are likely to incur high costs.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01761253","term_id":"NCT01761253"}}NCT01761253     

Determinants of elevated healthcare utilization in patients with COPD

Background

Chronic obstructive pulmonary disease (COPD) imparts a substantial economic burden on western health systems. Our objective was to analyze the determinants of elevated healthcare utilization among patients with COPD in a single-payer health system.

Methods

Three-hundred eighty-nine adults with COPD were matched 1:3 to controls by age, gender and area of residency. Total healthcare cost 5 years prior recruitment and presence of comorbidities were obtained from a computerized database. Health related quality of life (HRQoL) indices were obtained using validated questionnaires among a subsample of 177 patients.

Results

Healthcare utilization was 3.4-fold higher among COPD patients compared with controls (p < 0.001). The "most-costly" upper 25% of COPD patients (n = 98) consumed 63% of all costs. Multivariate analysis revealed that independent determinants of being in the "most costly" group were (OR; 95% CI): age-adjusted Charlson Comorbidity Index (1.09; 1.01 - 1.2), history of: myocardial infarct (2.87; 1.5 - 5.5), congestive heart failure (3.52; 1.9 - 6.4), mild liver disease (3.83; 1.3 - 11.2) and diabetes (2.02; 1.1 - 3.6). Bivariate analysis revealed that cost increased as HRQoL declined and severity of airflow obstruction increased but these were not independent determinants in a multivariate analysis.

Conclusion

Comorbidity burden determines elevated utilization for COPD patients. Decision makers should prioritize scarce health care resources to a better care management of the "most costly" patients.     

The Effects of Comorbidity on the Benefits and Harms of Treatment for Chronic Disease: A Systematic Review

Background

There are concerns about the potential for unintentional harms when clinical practice guidelines are applied to patients with multimorbidity. The objective was to summarize the evidence regarding the effect(s) of comorbidity on the outcomes of medication for an index chronic condition.

Methods

A systematic review was conducted of studies published in MEDLINE and Cochrane Trials before May 2012. The search strategy was constructed to identify articles indexed with “comorbidity” or a related term or by a given condition and one or more additional specified comorbid conditions. The search yielded 3252 articles, of which 37 passed the title/abstract screening process, and 22 were included after full-text review. An additional 23 articles were identified by screening the reference lists for included articles. Information was extracted on study design; population; therapy; comparison groups; outcome(s); main findings.

Findings

Indexing of articles was inconsistent, with no term for “multimorbidity,” and rare use of “comorbidity”. Only one article examined the effects of comorbidity per se, finding no benefit of tight control of DM among persons with high comorbidity, defined using a comorbidity index. The remainder examined pairs of conditions, the majority of which were post-hoc analyses of randomized controlled trials and which found no difference in outcomes according to whether a comorbid condition was present. Several demonstrated no difference or an increased risk of adverse outcome among persons with DM and tight control of HTN as compared to usual control. Several demonstrated lack of benefit of statins among persons with end-stage renal disease.

Conclusions

There is limited evidence regarding the effects of multiple comorbidities on treatment outcomes. The majority of studies demonstrated no effect of a single comorbid condition on outcomes. Additional studies examining a broad range of comorbidity are required, along with clear and consistent indexing to allow for improved synthesis of the evidence.     

Obsessive-Compulsive Disorder and Autism Spectrum Disorders: Longitudinal and Offspring Risk

Background

Despite substantial similarities and overlaps in the pathophysiology of obsessive-compulsive disorders (OCD) and autism spectrum disorders, little is known about the clinical and etiologic cohesion of these two disorders. We therefore aimed to determine the patterns of comorbidity, longitudinal risks, and shared familial risks between these disorders.

Methods

In a prospective study design we explored the effect of a prior diagnosis of OCD in patients and parents on the susceptibility to autism spectrum disorders and vice versa. Analyses were adjusted for sex, age, calendar year, parental age and place at residence at time of birth. As measures of relative risk incidence rate ratios (IRR) and accompanying 95% confidence intervals (CIs) were employed.

Results

The risk of a comorbid diagnosis of OCD in individuals with autism spectrum disorder and aggregation of autism spectrum disorders in offspring of parents with OCD were increased. Individuals first diagnosed with autism spectrum disorders had a 2-fold higher risk of a later diagnosis of OCD (IRR = 2.18, 95% CI = 1.91–2.48), whereas individuals diagnosed with OCD displayed a nearly 4-fold higher risk to be diagnosed with autism spectrum disorders (IRR = 3.91, 95% CI = 3.46–4.40) later in life. The observed associations were somewhat stronger for less severe types of autism spectrum disorders without a comorbid diagnosis of mental disabilities.

Conclusions

The high comorbidity, sequential risk, and shared familial risks between OCD and autism spectrum disorders are suggestive of partially shared etiological mechanisms. The results have implications for current gene-searching efforts and for clinical practice.