Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
2.
Colorectal Dis ; 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33002305

RESUMO

AIM: The aim was to assess the health utility of lung metastasectomy in the treatment of patients with colorectal cancer (CRC) using the EQ-5D-3L questionnaire. METHODS: Multidisciplinary CRC teams at 14 sites recruited patients to a two-arm randomized controlled trial-Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC). Remote randomization was used, stratified by site and with minimization for seven known confounders. Participants completed the EQ-5D-3L questionnaire together with other patient reported outcome measures at randomization and then again at 3, 6, 12 and 24 months. These were returned by post to the coordinating centre. RESULTS: Between December 2010 and December 2016, 93 participants were randomized, 91 of whom returned questionnaires. Survival and patient reported quality of life have been published previously, revealing no significant differences between the trial arms. Described here are patient reported data from the five dimensions of the EQ-5D-3L and the visual analogue scale (VAS) health state. No significant difference was seen at any time point. The estimated difference between control and metastasectomy patients was -0.23 (95% CI -0.113, 0.066) for the composite 0 to 1 index scale based on the descriptive system and 0.123 (95% CI -7.24, 7.49) for the 0 to 100 VAS scale. CONCLUSIONS: Following lung metastasectomy for CRC, no benefit was demonstrated for health utility, which alongside a lack of a survival or quality of life benefit calls into question the widespread use of the procedure.

3.
Arthritis Rheumatol ; 72(10): 1734-1740, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32515554

RESUMO

OBJECTIVE: In previous studies, atherosclerotic vascular events (AVEs) were shown to occur in ~10% of patients with systemic lupus erythematosus (SLE). We undertook this study to investigate the annual occurrence and potential risk factors for AVEs in a multinational, multiethnic inception cohort of patients with SLE. METHODS: A large 33-center cohort of SLE patients was followed up yearly between 1999 and 2017. AVEs were attributed to atherosclerosis based on SLE being inactive at the time of the AVE as well as typical atherosclerotic changes observed on imaging or pathology reports and/or evidence of atherosclerosis elsewhere. Analyses included descriptive statistics, rate of AVEs per 1,000 patient-years, and univariable and multivariable relative risk regression models. RESULTS: Of the 1,848 patients enrolled in the cohort, 1,710 had ≥1 follow-up visit after enrollment, for a total of 13,666 patient-years. Of these 1,710 patients, 3.6% had ≥1 AVEs attributed to atherosclerosis, for an event rate of 4.6 per 1,000 patient-years. In multivariable analyses, lower AVE rates were associated with antimalarial treatment (hazard ratio [HR] 0.54 [95% confidence interval (95% CI) 0.32-0.91]), while higher AVE rates were associated with any prior vascular event (HR 4.00 [95% CI 1.55-10.30]) and a body mass index of >40 kg/m2 (HR 2.74 [95% CI 1.04-7.18]). A prior AVE increased the risk of subsequent AVEs (HR 5.42 [95% CI 3.17-9.27], P < 0.001). CONCLUSION: The prevalence of AVEs and the rate of AVE accrual demonstrated in the present study is much lower than that seen in previously published data. This may be related to better control of both the disease activity and classic risk factors.

4.
Ann Rheum Dis ; 79(3): 356-362, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31915121

RESUMO

OBJECTIVES: Using a reversible multistate model, we prospectively examined neuropsychiatric (NP) events for attribution, outcome and association with health-related quality of life (HRQoL), in an international, inception cohort of systemic lupus erythematosus (SLE) patients. METHODS: Annual assessments for 19 NP events attributed to SLE and non-SLE causes, physician determination of outcome and patient HRQoL (short-form (SF)-36 scores) were measured. Time-to-event analysis and multistate modelling examined the onset, recurrence and transition between NP states. RESULTS: NP events occurred in 955/1827 (52.3%) patients and 592/1910 (31.0%) unique events were attributed to SLE. In the first 2 years of follow-up the relative risk (95% CI) for SLE NP events was 6.16 (4.96, 7.66) and non-SLE events was 4.66 (4.01, 5.43) compared with thereafter. Patients without SLE NP events at initial assessment had a 74% probability of being event free at 10 years. For non-SLE NP events the estimate was 48%. The majority of NP events resolved over 10 years but mortality was higher in patients with NP events attributed to SLE (16%) versus patients with no NPSLE events (6%) while the rate was comparable in patients with non-SLE NP events (7%) compared with patients with no non-SLE events (6%). Patients with NP events had lower SF-36 summary scores compared with those without NP events and resolved NP states (p<0.001). CONCLUSIONS: NP events occur most frequently around the diagnosis of SLE. Although the majority of events resolve they are associated with reduced HRQoL and excess mortality. Multistate modelling is well suited for the assessment of NP events in SLE.


Assuntos
Lúpus Eritematoso Sistêmico/psicologia , Vasculite Associada ao Lúpus do Sistema Nervoso Central/psicologia , Adulto , Feminino , Humanos , Estudos Longitudinais , Lúpus Eritematoso Sistêmico/mortalidade , Vasculite Associada ao Lúpus do Sistema Nervoso Central/mortalidade , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Análise Multinível , Estudos Prospectivos , Qualidade de Vida
5.
Arthritis Rheumatol ; 72(1): 67-77, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31390162

RESUMO

OBJECTIVE: To determine the frequency, clinical characteristics, associations, and outcomes of different types of peripheral nervous system (PNS) disease in a multiethnic/multiracial, prospective inception cohort of systemic lupus erythematosus (SLE) patients. METHODS: Patients were evaluated annually for 19 neuropsychiatric (NP) events including 7 types of PNS disease. SLE disease activity, organ damage, autoantibodies, and patient and physician assessment of outcome were measured. Time to event and linear regressions were used as appropriate. RESULTS: Of 1,827 SLE patients, 88.8% were female, and 48.8% were white. The mean ± SD age was 35.1 ± 13.3 years, disease duration at enrollment was 5.6 ± 4.2 months, and follow-up was 7.6 ± 4.6 years. There were 161 PNS events in 139 (7.6%) of 1,827 patients. The predominant events were peripheral neuropathy (66 of 161 [41.0%]), mononeuropathy (44 of 161 [27.3%]), and cranial neuropathy (39 of 161 [24.2%]), and the majority were attributed to SLE. Multivariate Cox regressions suggested longer time to resolution in patients with a history of neuropathy, older age at SLE diagnosis, higher SLE Disease Activity Index 2000 scores, and for peripheral neuropathy versus other neuropathies. Neuropathy was associated with significantly lower Short Form 36 (SF-36) physical and mental component summary scores versus no NP events. According to physician assessment, the majority of neuropathies resolved or improved over time, which was associated with improvements in SF-36 summary scores for peripheral neuropathy and mononeuropathy. CONCLUSION: PNS disease is an important component of total NPSLE and has a significant negative impact on health-related quality of life. The outcome is favorable for most patients, but our findings indicate that several factors are associated with longer time to resolution.


Assuntos
Doenças dos Nervos Cranianos/fisiopatologia , Lúpus Eritematoso Sistêmico/fisiopatologia , Vasculite Associada ao Lúpus do Sistema Nervoso Central/fisiopatologia , Doenças do Sistema Nervoso Periférico/fisiopatologia , Adulto , Fatores Etários , Estudos de Coortes , Doenças dos Nervos Cranianos/etiologia , Feminino , Humanos , Lúpus Eritematoso Sistêmico/complicações , Masculino , Pessoa de Meia-Idade , Mononeuropatias/etiologia , Mononeuropatias/fisiopatologia , Análise Multivariada , Doenças do Sistema Nervoso Periférico/etiologia , Modelos de Riscos Proporcionais , Índice de Gravidade de Doença , Adulto Jovem
6.
Arthritis Care Res (Hoboken) ; 72(12): 1800-1808, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31609532

RESUMO

OBJECTIVE: There is a paucity of data regarding health care costs associated with damage accrual in systemic lupus erythematosus. The present study was undertaken to describe costs associated with damage states across the disease course using multistate modeling. METHODS: Patients from 33 centers in 11 countries were enrolled in the Systemic Lupus International Collaborating Clinics (SLICC) inception cohort within 15 months of diagnosis. Annual data on demographics, disease activity, damage (SLICC/American College of Rheumatology Damage Index [SDI]), hospitalizations, medications, dialysis, and selected procedures were collected. Ten-year cumulative costs (Canadian dollars) were estimated by multiplying annual costs associated with each SDI state by the expected state duration using a multistate model. RESULTS: A total of 1,687 patients participated; 88.7% were female, 49.0% were white, mean ± SD age at diagnosis was 34.6 ± 13.3 years, and mean time to follow-up was 8.9 years (range 0.6-18.5 years). Mean annual costs were higher for those with higher SDI scores as follows: $22,006 (Canadian) (95% confidence interval [95% CI] $16,662, $27,350) for SDI scores ≥5 versus $1,833 (95% CI $1,134, $2,532) for SDI scores of 0. Similarly, 10-year cumulative costs were higher for those with higher SDI scores at the beginning of the 10-year interval as follows: $189,073 (Canadian) (95% CI $142,318, $235,827) for SDI scores ≥5 versus $21,713 (95% CI $13,639, $29,788) for SDI scores of 0. CONCLUSION: Patients with the highest SDI scores incur 10-year cumulative costs that are ~9-fold higher than those with the lowest SDI scores. By estimating the damage trajectory and incorporating annual costs, data on damage can be used to estimate future costs, which is critical knowledge for evaluating the cost-effectiveness of novel therapies.

7.
Lifetime Data Anal ; 25(4): 696-711, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30661194

RESUMO

For rheumatic diseases, Minimal Disease Activity (MDA) is usually defined as a composite outcome which is a function of several individual outcomes describing symptoms or quality of life. There is ever increasing interest in MDA but relatively little has been done to characterise the pattern of MDA over time. Motivated by the aim of improving the modelling of MDA in psoriatic arthritis, the use of a two-state model to estimate characteristics of the MDA process is illustrated when there is particular interest in prolonged periods of MDA. Because not all outcomes necessary to define MDA are measured at all clinic visits, a partially hidden multi-state model with latent states is used. The defining outcomes are modelled as conditionally independent given these latent states, enabling information from all visits, even those with missing data on some variables, to be used. Data from the Toronto Psoriatic Arthritis Clinic are analysed to demonstrate improvements in accuracy and precision from the inclusion of data from visits with incomplete information on MDA. An additional benefit of this model is that it can be extended to incorporate explanatory variables, which allows process characteristics to be compared between groups. In the example, the effect of explanatory variables, modelled through the use of relative risks, is also summarised in a potentially more clinically meaningful manner by comparing times in states, and probabilities of visiting states, between patient groups.


Assuntos
Progressão da Doença , Qualidade de Vida , Doenças Reumáticas , Algoritmos , Interpretação Estatística de Dados , Feminino , Humanos , Masculino , Modelos Estatísticos
8.
Arthritis Rheumatol ; 71(2): 281-289, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30375754

RESUMO

OBJECTIVE: To determine, in a large, multiethnic/multiracial, prospective inception cohort of patients with systemic lupus erythematosus (SLE), the frequency, attribution, clinical, and autoantibody associations with lupus psychosis and the short- and long-term outcomes as assessed by physicians and patients. METHODS: Patients were evaluated annually for 19 neuropsychiatric (NP) events including psychosis. Scores on the Systemic Lupus Erythematosus Disease Activity Index 2000, the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, and the Short Form 36 (SF-36) were recorded. Time to event and linear regressions were used as appropriate. RESULTS: Of 1,826 SLE patients, 88.8% were female and 48.8% were Caucasian. The mean ± SD age was 35.1 ± 13.3 years, the mean ± SD disease duration was 5.6 ± 4.2 months, and the mean ± SD follow-up period was 7.4 ± 4.5 years. There were 31 psychotic events in 28 of 1,826 patients (1.53%), and most patients had a single event (26 of 28 [93%]). In the majority of patients (20 of 25 [80%]) and events (28 of 31 [90%]), psychosis was attributed to SLE, usually either in the year prior to or within 3 years of SLE diagnosis. Positive associations (hazard ratios [HRs] and 95% confidence intervals [95% CIs]) with lupus psychosis were previous SLE NP events (HR 3.59 [95% CI 1.16-11.14]), male sex (HR 3.0 [95% CI 1.20-7.50]), younger age at SLE diagnosis (per 10 years) (HR 1.45 [95% CI 1.01-2.07]), and African ancestry (HR 4.59 [95% CI 1.79-11.76]). By physician assessment, most psychotic events resolved by the second annual visit following onset, in parallel with an improvement in patient-reported SF-36 summary and subscale scores. CONCLUSION: Psychosis is an infrequent manifestation of NPSLE. Generally, it occurs early after SLE onset and has a significant negative impact on health status. As determined by patient and physician report, the short- and long-term outlooks are good for most patients, although careful follow-up is required.


Assuntos
Vasculite Associada ao Lúpus do Sistema Nervoso Central/epidemiologia , Transtornos Psicóticos/epidemiologia , Adulto , Fatores Etários , Anticorpos Anticardiolipina/imunologia , Autoanticorpos/imunologia , Estudos de Coortes , Feminino , Humanos , Estimativa de Kaplan-Meier , Modelos Lineares , Inibidor de Coagulação do Lúpus/imunologia , Lúpus Eritematoso Sistêmico/epidemiologia , Lúpus Eritematoso Sistêmico/imunologia , Vasculite Associada ao Lúpus do Sistema Nervoso Central/imunologia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Transtornos Psicóticos/imunologia , Receptores de N-Metil-D-Aspartato/imunologia , Fatores Sexuais , Adulto Jovem , beta 2-Glicoproteína I/imunologia
9.
Arthritis Care Res (Hoboken) ; 70(10): 1478-1487, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29316357

RESUMO

OBJECTIVE: To determine the frequency, characteristics, and outcomes of cerebrovascular events (CerVEs), as well as clinical and autoantibody associations in a multiethnic/racial inception cohort of patients with systemic lupus erythematosus (SLE). METHODS: A total of 1,826 patients were assessed annually for 19 neuropsychiatric (NP) events, including 5 types of CerVEs: 1) stroke, 2) transient ischemia, 3) chronic multifocal ischemia, 4) subarachnoid/intracranial hemorrhage, and 5) sinus thrombosis. Global disease activity (Systemic Lupus Erythematosus Disease [SLE] Activity Index 2000), damage scores (SLE International Collaborating Clinics/American College of Rheumatology Damage Index), and Short Form 36 (SF-36) scores were collected. Time to event, linear and logistic regressions, and multistate models were used as appropriate. RESULTS: CerVEs were the fourth most frequent NP event: 82 of 1,826 patients had 109 events; of these events, 103 were attributed to SLE, and 44 were identified at the time of enrollment. The predominant events were stroke (60 of 109 patients) and transient ischemia (28 of 109 patients). CerVEs were associated with other NP events attributed to SLE, non-SLE-attributed NP events, African ancestry (at US SLICC sites), and increased organ damage scores. Lupus anticoagulant increased the risk of first stroke and sinus thrombosis and transient ischemic attack. Physician assessment indicated resolution or improvement in the majority of patients, but patients reported sustained reduction in SF-36 summary and subscale scores following a CerVE. CONCLUSION: CerVEs, the fourth most frequent NP event in SLE, are usually attributable to lupus. In contrast to good physician-reported outcomes, patients reported a sustained reduction in health-related quality of life following a CerVE.


Assuntos
Transtornos Cerebrovasculares/imunologia , Lúpus Eritematoso Sistêmico/complicações , Adulto , Transtornos Cerebrovasculares/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Adulto Jovem
10.
J R Stat Soc Ser C Appl Stat ; 67(2): 481-500, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29371746

RESUMO

In psoriatic arthritis, it is important to understand the joint activity (represented by swelling and pain) and damage processes because both are related to severe physical disability. The paper aims to provide a comprehensive investigation into both processes occurring over time, in particular their relationship, by specifying a joint multistate model at the individual hand joint level, which also accounts for many of their important features. As there are multiple hand joints, such an analysis will be based on the use of clustered multistate models. Here we consider an observation level random-effects structure with dynamic covariates and allow for the possibility that a subpopulation of patients is at minimal risk of damage. Such an analysis is found to provide further understanding of the activity-damage relationship beyond that provided by previous analyses. Consideration is also given to the modelling of mean sojourn times and jump probabilities. In particular, a novel model parameterization which allows easily interpretable covariate effects to act on these quantities is proposed.

11.
J R Stat Soc Ser C Appl Stat ; 67(4): 841-860, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31105343

RESUMO

Bidirectional changes over time in the estimated glomerular filtration rate and in urine protein content are of interest for the treatment and management of patients with lupus nephritis. Although these processes may be modelled by separate multistate models, the processes are likely to be correlated within patients. Motivated by the lupus nephritis application, we develop a new multistate modelling framework where subject-specific random effects are introduced to account for the correlations both between the processes and within patients over time. Models are fitted by using bespoke code in standard statistical software. A variety of forms for the random effects are introduced and evaluated by using the data from the Systemic Lupus International Collaborating Clinics.

12.
Arthritis Care Res (Hoboken) ; 70(9): 1294-1302, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29193883

RESUMO

OBJECTIVE: Little is known about the long-term costs of lupus nephritis (LN). The costs were compared between patients with and without LN using multistate modeling. METHODS: Patients from 32 centers in 11 countries were enrolled in the Systemic Lupus International Collaborating Clinics inception cohort within 15 months of diagnosis and provided annual data on renal function, hospitalizations, medications, dialysis, and selected procedures. LN was diagnosed by renal biopsy or the American College of Rheumatology classification criteria. Renal function was assessed annually using the estimated glomerular filtration rate (GFR) or estimated proteinuria. A multistate model was used to predict 10-year cumulative costs by multiplying annual costs associated with each renal state by the expected state duration. RESULTS: A total of 1,545 patients participated; 89.3% were women, the mean ± age at diagnosis was 35.2 ± 13.4 years, 49% were white, and the mean followup duration was 6.3 ± 3.3 years. LN developed in 39.4% of these patients by the end of followup. Ten-year cumulative costs were greater in those with LN and an estimated glomerular filtration rate (GFR) <30 ml/minute ($310,579 2015 Canadian dollars versus $19,987 if no LN and estimated GFR >60 ml/minute) or with LN and estimated proteinuria >3 gm/day ($84,040 versus $20,499 if no LN and estimated proteinuria <0.25 gm/day). CONCLUSION: Patients with estimated GFR <30 ml/minute incurred 10-year costs 15-fold higher than those with normal estimated GFR. By estimating the expected duration in each renal state and incorporating associated annual costs, disease severity at presentation can be used to anticipate future health care costs. This is critical knowledge for cost-effectiveness evaluations of novel therapies.


Assuntos
Nefrite Lúpica/economia , Adulto , Estudos de Coortes , Feminino , Custos de Cuidados de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Econômicos , Adulto Jovem
13.
J R Stat Soc Ser C Appl Stat ; 66(4): 669-690, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28706323

RESUMO

Many psoriatic arthritis patients do not progress to permanent joint damage in any of the 28 hand joints, even under prolonged follow-up. This has led several researchers to fit models that estimate the proportion of stayers (those who do not have the propensity to experience the event of interest) and to characterize the rate of developing damaged joints in the movers (those who have the propensity to experience the event of interest). However, when fitted to the same data, the paper demonstrates that the choice of model for the movers can lead to widely varying conclusions on a stayer population, thus implying that, if interest lies in a stayer population, a single analysis should not generally be adopted. The aim of the paper is to provide greater understanding regarding estimation of a stayer population by comparing the inferences, performance and features of multiple fitted models to real and simulated data sets. The models for the movers are based on Poisson processes with patient level random effects and/or dynamic covariates, which are used to induce within-patient correlation, and observation level random effects are used to account for time varying unobserved heterogeneity. The gamma, inverse Gaussian and compound Poisson distributions are considered for the random effects.

14.
Stat Biosci ; 8(2): 310-332, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27729945

RESUMO

In longitudinal randomised trials and observational studies within a medical context, a composite outcome-which is a function of several individual patient-specific outcomes-may be felt to best represent the outcome of interest. As in other contexts, missing data on patient outcome, due to patient drop-out or for other reasons, may pose a problem. Multiple imputation is a widely used method for handling missing data, but its use for composite outcomes has been seldom discussed. Whilst standard multiple imputation methodology can be used directly for the composite outcome, the distribution of a composite outcome may be of a complicated form and perhaps not amenable to statistical modelling. We compare direct multiple imputation of a composite outcome with separate imputation of the components of a composite outcome. We consider two imputation approaches. One approach involves modelling each component of a composite outcome using standard likelihood-based models. The other approach is to use linear increments methods. A linear increments approach can provide an appealing alternative as assumptions concerning both the missingness structure within the data and the imputation models are different from the standard likelihood-based approach. We compare both approaches using simulation studies and data from a randomised trial on early rheumatoid arthritis patients. Results suggest that both approaches are comparable and that for each, separate imputation offers some improvement on the direct imputation of a composite outcome.

15.
Stat Med ; 35(30): 5701-5716, 2016 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-27501256

RESUMO

In psoriatic arthritis, many patients do not develop permanent joint damage even after a prolonged follow-up. This has led several authors to consider the possibility of a subpopulation of stayers (those who do not have the propensity to experience the event of interest), as opposed to assuming the entire population consist of movers (those who have the propensity to experience the event of interest). In addition, it is recognised that the damaged joints process may act very differently across different joint areas, particularly the hands, feet and large joints. From a clinical perspective, interest lies in identifying possible relationships between the damaged joints processes in these joint areas for the movers and estimating the proportion of stayers in these joint areas, if they exist. For this purpose, this paper proposes a novel trivariate mover-stayer model consisting of mover-stayer truncated negative binomial margins, and patient-level dynamic covariates and random effects in the models for the movers and stayers, respectively. The model is then extended to have a two-level mover-stayer structure for its margins so that the nature of the stayer property can be investigated. A particularly attractive feature of the proposed models is that only an optimisation routine is required in their model fitting procedures. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.


Assuntos
Artrite Psoriásica/complicações , Artropatias/etiologia , Biometria , Humanos , Modelos Estatísticos
16.
Diagn Histopathol (Oxf) ; 22(7): 246-252, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27559362

RESUMO

A brief survey is provided of common designs for medical studies and important issues in their implementation. The designs discussed include those for laboratory studies, clinical trials, cohort studies, case-control and related studies, and diagnostic studies.

17.
Arthritis Rheumatol ; 68(8): 1932-44, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26991067

RESUMO

OBJECTIVE: To study bidirectional change and predictors of change in estimated glomerular filtration rate (GFR) and proteinuria in lupus nephritis (LN) using a multistate modeling approach. METHODS: Patients in the Systemic Lupus International Collaborating Clinics inception cohort were classified annually into estimated GFR state 1 (>60 ml/minute), state 2 (30-60 ml/minute), or state 3 (<30 ml/minute) and estimated proteinuria state 1 (<0.25 gm/day), state 2 (0.25-3.0 gm/day), or state 3 (>3.0 gm/day), or end-stage renal disease (ESRD) or death. Using multistate modeling, relative transition rates between states indicated improvement and deterioration. RESULTS: Of 1,826 lupus patients, 700 (38.3%) developed LN. During a mean ± SD follow-up of 5.2 ± 3.5 years, the likelihood of improvement in estimated GFR and estimated proteinuria was greater than the likelihood of deterioration. After 5 years, 62% of patients initially in estimated GFR state 3 and 11% of patients initially in estimated proteinuria state 3 transitioned to ESRD. The probability of remaining in the initial states 1, 2, and 3 was 85%, 11%, and 3%, respectively, for estimated GFR and 62%, 29%, and 4%, respectively, for estimated proteinuria. Male sex predicted improvement in estimated GFR states; older age, race/ethnicity, higher estimated proteinuria state, and higher renal biopsy chronicity scores predicted deterioration. For estimated proteinuria, race/ethnicity, earlier calendar years, damage scores without renal variables, and higher renal biopsy chronicity scores predicted deterioration; male sex, presence of lupus anticoagulant, class V nephritis, and mycophenolic acid use predicted less improvement. CONCLUSION: In LN, the expected improvement or deterioration in renal outcomes can be estimated by multistate modeling and is preceded by identifiable risk factors. New therapeutic interventions for LN should meet or exceed these expectations.


Assuntos
Taxa de Filtração Glomerular , Falência Renal Crônica/etiologia , Nefrite Lúpica/complicações , Nefrite Lúpica/fisiopatologia , Proteinúria/etiologia , Adulto , Feminino , Humanos , Internacionalidade , Estudos Longitudinais , Masculino , Modelos Estatísticos
18.
Arthritis Care Res (Hoboken) ; 68(3): 388-93, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26315478

RESUMO

OBJECTIVE: To explore methods for statistical modelling of minimal disease activity (MDA) based on data from intermittent clinic visits. METHODS: The analysis was based on a 2-state model. Comparisons were made between analyses based on "complete case" data from visits at which MDA status was known, and the use of hidden model methodology that incorporated information from visits at which only some MDA defining criteria could be established. Analyses were based on an observational psoriatic arthritis cohort. RESULTS: With data from 856 patients and 7,024 clinic visits, analysis was based on virtually all visits, although only 62.6% provided enough information to determine MDA status. Estimated mean times for an episode of MDA varied from 4.18 years to 3.10 years, with smaller estimates derived from the hidden 2-state model analysis. Over a 10-year period, the estimated expected times spent in MDA episodes of longer than 1 year was 3.90 to 4.22, and the probability of having such an MDA episode was estimated to be 0.85 to 0.91, with longer times and greater probabilities seen with the hidden 2-state model analysis. CONCLUSION: A 2-state model provides a useful framework for the analysis of MDA. Use of data from visits at which MDA status can not be determined provide more precision, and notable differences are seen in estimated quantities related to MDA episodes based on complete case and hidden 2-state model analyses. The possibility of bias, as well as loss of precision, should be recognized when complete case analyses are used.


Assuntos
Artrite Psoriásica/diagnóstico , Modelos Estatísticos , Artrite Psoriásica/patologia , Artrite Psoriásica/fisiopatologia , Artrite Psoriásica/terapia , Avaliação da Deficiência , Humanos , Exame Físico , Valor Preditivo dos Testes , Prognóstico , Índice de Gravidade de Doença , Inquéritos e Questionários , Fatores de Tempo
19.
Rheumatology (Oxford) ; 55(2): 252-62, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26342222

RESUMO

OBJECTIVE: To determine nephritis outcomes in a prospective multi-ethnic/racial SLE inception cohort. METHODS: Patients in the Systemic Lupus International Collaborating Clinics inception cohort (≤15 months of SLE diagnosis) were assessed annually for estimated glomerular filtration rate (eGFR), proteinuria and end-stage renal disease (ESRD). Health-related quality of life was measured by the Short Form (36 questions) health survey questionnaire (SF-36) subscales, mental and physical component summary scores. RESULTS: There were 1827 patients, 89% females, mean (s.d.) age 35.1 (13.3) years. The mean (s.d.) SLE duration at enrolment was 0.5 (0.3) years and follow-up 4.6 (3.4) years. LN occurred in 700 (38.3%) patients: 566/700 (80.9%) at enrolment and 134/700 (19.1%) during follow-up. Patients with nephritis were younger, more frequently men and of African, Asian and Hispanic race/ethnicity. The estimated overall 10-year incidence of ESRD was 4.3% (95% CI: 2.8%, 5.8%), and with nephritis was 10.1% (95% CI: 6.6%, 13.6%). Patients with nephritis had a higher risk of death (HR = 2.98, 95% CI: 1.48, 5.99; P = 0.002) and those with eGFR <30 ml/min at diagnosis had lower SF-36 physical component summary scores (P < 0.01) and lower Physical function, Physical role and Bodily pain scores. Over time, patients with abnormal eGFR and proteinuria had lower SF-36 mental component summary (P ≤ 0.02) scores compared to patients with normal values. CONCLUSION: LN occurred in 38.3% of SLE patients, frequently as the initial presentation, in a large multi-ethnic inception cohort. Despite current standard of care, nephritis was associated with ESRD and death, and renal insufficiency was linked to lower health-related quality of life. Further advances are required for the optimal treatment of LN.


Assuntos
Grupos Étnicos , Nefrite Lúpica/etnologia , Avaliação de Resultados em Cuidados de Saúde , Adulto , Progressão da Doença , Feminino , Seguimentos , Saúde Global , Humanos , Incidência , Nefrite Lúpica/diagnóstico , Masculino , Estudos Prospectivos , Qualidade de Vida , Fatores de Risco , Inquéritos e Questionários , Taxa de Sobrevida/tendências
20.
Stat Methods Med Res ; 25(5): 2014-2020, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-24201470

RESUMO

For semi-continuous data which are a mixture of true zeros and continuously distributed positive values, the use of two-part mixed models provides a convenient modelling framework. However, deriving population-averaged (marginal) effects from such models is not always straightforward. Su et al. presented a model that provided convenient estimation of marginal effects for the logistic component of the two-part model but the specification of marginal effects for the continuous part of the model presented in that paper was based on an incorrect formulation. We present a corrected formulation and additionally explore the use of the two-part model for inferences on the overall marginal mean, which may be of more practical relevance in our application and more generally.


Assuntos
Modelos Estatísticos , Artrite Psoriásica/genética , Artrite Psoriásica/patologia , Artrite Psoriásica/fisiopatologia , Interpretação Estatística de Dados , Feminino , Antígeno HLA-B27/genética , Humanos , Modelos Logísticos , Estudos Longitudinais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA