Jose M. Valderas

Defining Comorbidity: Implications for Understanding Health and Health Services

Comorbidity is associated with worse health outcomes, more complex clinical management, and increased health care costs. There is no agreement, however, on the meaning of the term, and related constructs, such as multimorbidity, morbidity burden, and patient complexity, are not well conceptualized. In this article, we review definitions of comorbidity and their relationship to related constructs. We show that the value of a given construct lies in its ability to explain a particular phenomenon of interest within the domains of (1) clinical care, (2) epidemiology, or (3) health services planning and financing. Mechanisms that may underlie the coexistence of 2 or more conditions in a patient (direct causation, associated risk factors, heterogeneity, independence) are examined, and the implications for clinical care considered. We conclude that the more precise use of constructs, as proposed in this article, would lead to improved research into the phenomenon of ill health in clinical care, epidemiology, and health services.

El Cuestionario de Salud SF-36 español: una década de experiencia y nuevos desarrollos

Objetivo: El Cuestionario SF-36 es uno de los instrumentos de Calidad de Vida Relacionada con la Salud (CVRS) mas utilizados y evaluados. Tras una decada de uso este articulo revisa criticamente el contenido, propiedades metricas y nuevos desarrollos de la version espanola. Metodos: Revision de los articulos indizados en Medline (PubMed) y en las bases de datos IBECS e IME que han utilizado la version espanola del cuestionario. Se seleccionaron los articulos con informacion sobre modelo de medida, fiabilidad, validez y sensibilidad al cambio del instrumento. Resultados: Se encontraron 79 articulos, 17 de los cuales describian caracteristicas metricas del cuestionario. En el 96% las escalas superaron el estandar propuesto de fiabilidad (α de Cronbach) de 0,7. Las estimaciones agrupadas obtenidas por metaanalisis fueron superiores a 0,7 en todos los casos. El SF-36 mostro buena discriminacion entre grupos de gravedad, correlacion moderada con indicadores clinicos y alta con otros instrumentos de CVRS. El SF-36 predijo mortalidad y detecto mejoria tras la angioplastia coronaria, la cirugia de hipertrofia prostatica benigna o la ventilacion domiciliaria no invasiva. Los nuevos desarrollos descritos (puntuaciones basadas en normas, la version 2, el SF-12 y el SF-8) mejoraron sus propiedades metricas y su interpretacion. Conclusiones: El SF-36, conjuntamente con las nuevas versiones desarrolladas, es un instrumento muy adecuado para su uso en investigacion y en la practica clinica.

Epidemiology and impact of multimorbidity in primary care: a retrospective cohort study

BACKGROUND In developed countries, primary health care increasingly involves the care of patients with multiple chronic conditions, referred to as multimorbidity. AIM To describe the epidemiology of multimorbidity and relationships between multimorbidity and primary care consultation rates and continuity of care. DESIGN OF STUDY Retrospective cohort study. SETTING Random sample of 99 997 people aged 18 years or over registered with 182 general practices in England contributing data to the General Practice Research Database. METHOD Multimorbidity was defined using two approaches: people with multiple chronic conditions included in the Quality and Outcomes Framework, and people identified using the Johns Hopkins University Adjusted Clinical Groups (ACG®) Case-Mix System. The determinants of multimorbidity (age, sex, area deprivation) and relationships with consultation rate and continuity of care were examined using regression models. RESULTS Sixteen per cent of patients had more than one chronic condition included in the Quality and Outcomes Framework, but these people accounted for 32% of all consultations. Using the wider ACG list of conditions, 58% of people had multimorbidity and they accounted for 78% of consultations. Multimorbidity was strongly related to age and deprivation. People with multimorbidity had higher consultation rates and less continuity of care compared with people without multimorbidity. CONCLUSION Multimorbidity is common in the population and most consultations in primary care involve people with multimorbidity. These people are less likely to receive continuity of care, although they may be more likely to gain from it.

The impact of measuring patient-reported outcomes in clinical practice: a systematic review of the literature

ObjectiveThe purpose of this paper is to summarize the best evidence regarding the impact of providing patient-reported outcomes (PRO) information to health care professionals in daily clinical practice.MethodsSystematic review of randomized clinical trials (Medline, Cochrane Library; reference lists of previous systematic reviews; and requests to authors and experts in the field).ResultsOut of 1,861 identified references published between 1978 and 2007, 34 articles corresponding to 28 original studies proved eligible. Most trials (19) were conducted in primary care settings performed in the USA (21) and assessed adult patients (25). Information provided to professionals included generic health status (10), mental health (14), and other (6). Most studies suffered from methodologic limitations, including analysis that did not correspond with the unit of allocation. In most trials, the impact of PRO was limited. Fifteen of 23 studies (65%) measuring process of care observed at least one significant result favoring the intervention, as did eight of 17 (47%) that measured outcomes of care.ConclusionsMethodological concerns limit the strength of inference regarding the impact of providing PRO information to clinicians. Results suggest great heterogeneity of impact; contexts and interventions that will yield important benefits remain to be clearly defined.

The prevalence of multimorbidity in primary care and its effect on health care utilization and cost

INTRODUCTION Multimorbidity is common among the heterogeneous primary care population, but little data exist on its association with health care utilization or cost. OBJECTIVE The aim of this observational study was to examine the prevalence and associated health care utilization and cost of patients with multimorbidity. METHODS All patients >50 years of age were eligible for the study which took place in three primary care practices in the West of Ireland. Chronic medical conditions and associated health care utilization in primary and secondary care were identified through patient record review. RESULTS In a sample of 3309 patients in the community, the prevalence of multimorbidity was 66.2% (95% CI: 64.5-67.8) in those >50 years of age. Health care utilization and cost was significantly increased among patients with multimorbidity (P < 0.001). After multivariate adjustment for age, gender and free medical care eligibility, the addition of each chronic condition led to an associated increase in primary care consultations (P = 0.001) (11.9 versus 3.7 for >4 conditions versus 0 conditions); hospital out-patient visits (P = 0.001) (3.6 versus 0.6 for >4 conditions versus 0 conditions); hospital admissions (P = 0.01) [adjusted odds ratio (OR) of 4.51 for >4 conditions versus 0 conditions] and total health care costs (P < 0.001) (€4,096.86 versus €760.20 for >4 conditions versus 0 conditions) over the previous 12 months. CONCLUSIONS Multimorbidity is very common in primary care and in a system with strong gatekeeping is associated with high health care utilization and cost across the health care system. Interventions to address quality and cost associated with multimorbidity must focus on primary as well as secondary care.

Prevalence, determinants and patterns of multimorbidity in primary care: a systematic review of observational studies.

Introduction Multimorbidity is a major concern in primary care. Nevertheless, evidence of prevalence and patterns of multimorbidity, and their determinants, are scarce. The aim of this study is to systematically review studies of the prevalence, patterns and determinants of multimorbidity in primary care. Methods Systematic review of literature published between 1961 and 2013 and indexed in Ovid (CINAHL, PsychINFO, Medline and Embase) and Web of Knowledge. Studies were selected according to eligibility criteria of addressing prevalence, determinants, and patterns of multimorbidity and using a pretested proforma in primary care. The quality and risk of bias were assessed using STROBE criteria. Two researchers assessed the eligibility of studies for inclusion (Kappa  = 0.86). Results We identified 39 eligible publications describing studies that included a total of 70,057,611 patients in 12 countries. The number of health conditions analysed per study ranged from 5 to 335, with multimorbidity prevalence ranging from 12.9% to 95.1%. All studies observed a significant positive association between multimorbidity and age (odds ratio [OR], 1.26 to 227.46), and lower socioeconomic status (OR, 1.20 to 1.91). Positive associations with female gender and mental disorders were also observed. The most frequent patterns of multimorbidity included osteoarthritis together with cardiovascular and/or metabolic conditions. Conclusions Well-established determinants of multimorbidity include age, lower socioeconomic status and gender. The most prevalent conditions shape the patterns of multimorbidity. However, the limitations of the current evidence base means that further and better designed studies are needed to inform policy, research and clinical practice, with the goal of improving health-related quality of life for patients with multimorbidity. Standardization of the definition and assessment of multimorbidity is essential in order to better understand this phenomenon, and is a necessary immediate step.

Effect of financial incentives on incentivised and non-incentivised clinical activities: longitudinal analysis of data from the UK Quality and Outcomes Framework

Objective To investigate whether the incentive scheme for UK general practitioners led them to neglect activities not included in the scheme. Design Longitudinal analysis of achievement rates for 42 activities (23 included in incentive scheme, 19 not included) selected from 428 identified indicators of quality of care. Setting 148 general practices in England (653 500 patients). Main outcome measures Achievement rates projected from trends in the pre-incentive period (2000-1 to 2002-3) and actual rates in the first three years of the scheme (2004-5 to 2006-7). Results Achievement rates improved for most indicators in the pre-incentive period. There were significant increases in the rate of improvement in the first year of the incentive scheme (2004-5) for 22 of the 23 incentivised indicators. Achievement for these indicators reached a plateau after 2004-5, but quality of care in 2006-7 remained higher than that predicted by pre-incentive trends for 14 incentivised indicators. There was no overall effect on the rate of improvement for non-incentivised indicators in the first year of the scheme, but by 2006-7 achievement rates were significantly below those predicted by pre-incentive trends. Conclusions There were substantial improvements in quality for all indicators between 2001 and 2007. Improvements associated with financial incentives seem to have been achieved at the expense of small detrimental effects on aspects of care that were not incentivised.

Provision of feedback on perceived health status to health care professionals: a systematic review of its impact.

OBJECTIVE To assess the impact on the process and the outcomes of care of feeding back information on perceived health status to health care professionals in clinical practice. DESIGN Systematic review of controlled trials. DATA IDENTIFICATION Search in electronic databases (MEDLINE 1966-1997), manual searches, and requests to experts in the field. DATA ANALYSIS Differences between intervention and control group were considered in process of care (use of health services, diagnosis, and treatment), patient outcomes (health status), and patient satisfaction. In a subgroup of 13 interventions that dealt with the provision of feedback about the patients mental health, the impact on the process of care was subjected to meta-analysis. RESULTS We identified 21 studies that satisfied the selection criteria. Eleven of 20 (55%) found significant differences (P <0.05) in at least 1 of the process indicators in favor of the intervention group. Of 11 trials that assessed patient outcomes, only 4 (36%) detected significant improvements. A similar trend but lower percentages were observed among the 8 interventions that provided general health status information. Eleven interventions that evaluated feedback information about the patients mental health status showed a higher rate of diagnosis in the intervention group (combined odds ratio [OR]=1.91; 95% confidence interval [CI] 1.28 to 2.83). Seven of 9 studies evaluating treatment failed to show an effect on this indicator (combined OR=1.15; 95% CI 0.76 to 1.75). CONCLUSIONS The provision of feedback on perceived health status to health professionals seems to have an effect on the process of care but not on patient functional or health status. This is especially true with regard to mental health status information. Nevertheless, there is still need for a more through evaluation of this type of intervention.

Patient reported outcome measures: a model-based classification system for research and clinical practice

PurposeThe umbrella term Patient Reported Outcomes (PRO) has been successfully proposed for instruments measuring perceived health outcomes, but its relationship to current conceptual models remains to be established. Our aim was to develop a classification system for PRO measures based on a valid conceptual model.MethodsWe reviewed models and classification schemes of health outcomes and integrated them in a common conceptual framework, based on the models by Wilson and Cleary and the International Classification of Functioning (ICF). We developed a cross-classification system based on the minimum common set of consistent concepts identified in previous classifications, and specified categories based on the WHO International Classifications (ICD-10, and ICF). We exemplified the use of the classification system with selected PRO instruments.ResultsWe identified three guiding concepts: (1) construct (the measurement object); (2) population (based on age, gender, condition, and culture); and (3) measurement model (dimensionality, metric, and adaptability). The application of the system to selected PRO measures demonstrated the feasibility of its use, and showed that most of them actually assess more than one construct.ConclusionThis classification system of PRO measures, based on a valid integrated conceptual model, should allow the classification of most currently used instruments and may facilitate a more adequate selection and application of these instruments.

The Spanish version of the Short Form 36 Health Survey: a decade of experience and new developments

OBJECTIVE The Short Form-36 Health Survey (SF-36) is one of the most widely used and evaluated generic health-related quality of life (HRQL) questionnaires. After almost a decade of use in Spain, the present article critically reviews the content and metric properties of the Spanish version, as well as its new developments. METHODS A review of indexed articles that used the Spanish version of the SF-36 was performed in Medline (PubMed), the Spanish bibliographic databases IBECS and IME. Articles that provided information on the measurement model, reliability, validity, and responsiveness to change of the instrument were selected. RESULTS Seventy-nine articles were found, of which 17 evaluated the metric characteristics of the questionnaire. The reliability of the SF-36 scales was higher than the suggested standard (Cronbachs alpha) of 0.7 in 96% of the evaluations. Grouped evaluations obtained by meta-analysis were higher than 0.7 in all cases. The SF-36 showed good discrimination among severity groups, moderate correlations with clinical indicators, and high correlations with other HRQL instruments. Moreover, questionnaire scores predicted mortality and were able to detect improvement due to therapeutic interventions such as coronary angioplasty, benign prostatic hyperplasia surgery, and non-invasive positive pressure home ventilation. The new developments (norm-based scoring, version 2, the SF-12 and SF-8) improved both the metric properties and interpretation of the questionnaire. CONCLUSIONS The Spanish version of the SF-36 and its recently developed versions is a suitable instrument for use in medical research, as well as in clinical practice.