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Often postdropout responses (PDR) in study dropouts are identified from death/disease registries or other medical records. If all dropout is random, then use of postdropout responses while censoring other subjects at date of dropout (CDO/PDR) will bias non-parametric survival probability estimates downward. Censoring all individuals at the last date of study contact, ignoring postdropout information (CDO) will produce unbiased nonparametric survival estimates. As onset of the response sometimes incapacitates the individual, preventing further study participation, dropout is often positively correlated with response. In this case CDO/PDR tends to prevent nonparametric survival overestimation but could lead to underestimation. When all of the responses in dropouts are identified, then regardless of dropout cause, use of all postdropout information, together with censoring all other subjects at time of analysis (CTA/PDR) will produce unbiased minimum variance estimates. We analyze the bias properties of nonparametric survival estimates produced using CDO/PDR, CDO, and CTA/PDR censoring mechanisms under various causes of study dropout and degrees of postdropout response recovery. The goal is to identify which of these censoring methods best incorporates postdropout information. Postdropout information may create interval-censored data. To facilitate statistical analysis of such data, the likelihood function is formulated in terms of the hazard. This results in computationally simple nonparametric estimates and covariances for interval-censored and left-truncated data. An application to estimation of acquired immune deficiency (AIDS)-free time after human immunodeficiency virus (HIV)-l seroconversion using data from a long-term cohort study with considerable dropout is presented. Upper and lower bound estimates for AIDS-free survival probabilities derived using CDO and CDO/PDR are shown to be quite close when compared to the underlying variance of these estimates. KEY WORDS: Censoring method; Dropout; Interval censoring; Nonparametric survival analysis; Postdropout response; Truncation., Accurate projection of the future impact of the acquired immune deficiency (AIDS) epidemic requires knowledge of the hazard of AIDS as a function of time elapsed from human immunodeficiency virus [...]

Objective: To estimate expected survival time among homosexual men infected with the human immunodeficiency virus type 1 (HIV-1) by (1) the calendar period before (1985-1988) and after (1989-1993) the widespread availability of acquired immunodeficiency syndrome (AIDS) treatments with antiretroviral and prophylactic interventions, and (2) stage of HIV disease.Design: A prospective cohort study. A group of HIV-1-infected homosexual men were followed from July 1985 through June 1993 and evaluated every 6 months for the presence of clinical symptoms and measurement of the CD4 cell count. To measure the effectiveness of AIDS therapies in this nonrandomized study, we used 2 calendar periods as proxy measures of relative intensity of exposure to antiretroviral therapy. Stage of infection was defined by CD4 cell count and presence of HIV-related clinical symptoms or AIDS.Setting and Study Participants: Homosexual men infected with HIV-1 from the Multicenter AIDS Cohort Study.Main Outcome Measure: Survival time based on stage of HIV infection.Results: The percentage of HIV-1-infected individuals free of AIDS and clinical symptoms at baseline who survived 2.5 years according to baseline CD4 cell counts of 0 to 0.100, 0.101 to 0.200, and 0.201 to 0.350 x 10(9)/L was 22%, 53%, and 83%, respectively, for the 1985-1988 calendar period, compared with 54%, 71%, and 91%, respectively, for men in the 1989-1993 calendar period. Among men free of AIDS with CD4 cell counts of greater than 0.350 x 10(9)/L, the relative hazard of mortality was 1.6 to 2.3 times higher for those with clinical symptoms compared with those free of clinical symptoms.Conclusions: Survival of AIDS-free HIV-1-infected individuals with CD4 cell counts of less than 0.350 x 10(9)/L has improved since antiretroviral and HIV prophylactic treatments have become available, but the long-term prognosis remains poor. [ABSTRACT FROM AUTHOR]

Objective: To examine the safety and effectiveness of a low-molecular-weight heparin in the prevention of thromboembolism in patients with recent spinal cord injury and complete motor paralysis.Design: Randomized evaluation of two heparin regimens in 41 consecutive patients meeting eligibility requirements for anticoagulant prophylaxis. Daily bedside examinations were supplemented by serial venous flow studies; suspicious or positive tests were confirmed by venography.Intervention: Standard heparin, 5000 units subcutaneously three times a day; low-molecular-weight heparin 3500 anti-Xa units subcutaneously once daily.Measurements and Main Results: Five patients in the standard heparin group had thrombotic events, including two patients with fatal pulmonary embolism; two other patients had bleeding severe enough to necessitate withdrawing the heparin. The cumulative event rate was 34.7% (95% CI, 13.7% to 55.2%). None of the patients treated with low-molecular-weight heparin had thrombosis or bleeding (CI, 0% to 14%). The difference between the two groups was significant (P = 0.006, log-rank test).Conclusions: Low-molecular-weight heparin is safe and effective in the prevention of thromboembolism in selected patients with spinal cord injury and complete motor paralysis, and is superior to standard heparin in fixed doses of 5000 units three times a day. [ABSTRACT FROM AUTHOR]

Objective: To determine the degree of compliance with clinical standards among hospitals for care of breast cancer patients and account for variations in compliance.Design: Analysis of cancer registry data submitted to the American Cancer Society, Illinois Division, Chicago, for a concurrent prospective descriptive study of breast cancer, supplemented by other hospital data from public sources.Setting: Ninety-nine Illinois hospitals evenly distributed among rural counties, counties with small cities outside the Chicago metropolitan area, exurban counties in the Chicago metropolitan area, suburban Cook County, and urban Chicago.Patients: A total of 5766 newly diagnosed patients with histologically confirmed breast cancer in 1988, representing 84% of the estimated 6900 new cases in the state for that year.Main Outcome Measures: Descriptive statistics and multiple linear regression analyses of five dependent quality variables from clinical indicators related to early diagnosis, hormone receptor determination, adjuvant therapy, radiation therapy, and axillary lymph node dissection.Results: At the hospitals studied, (1) late stage (IIb through IV) at diagnosis was associated with urban location, higher proportion of poorly insured patients, fewer breast cancer cases treated, and lower oncology charges (proportion of variance explained, R2 = .50, P less than .00001); (2) omission of hormone receptor test for stages II through IV was associated with urban location and higher proportion of poorly insured patients (R2 = .18, P less than .00003); and (3) omission of indicated radiation therapy was associated with urban location and fewer breast cancer cases (R2 = .21, P less than .00001). Omission of adjuvant therapy and omission of axillary lymph node dissection were not significantly associated with any of the hospital variables examined.Conclusions: The findings suggest that there is a group of urban hospitals, generally small and marginally reimbursed, where comprehensive diagnosis and treatment of breast cancer are not obtained. [ABSTRACT FROM AUTHOR]

Background: The coronavirus disease 2019 (COVID-19) global pandemic drastically impacted the health system and the research community. As a result, research institutions and funding agencies recommended a moratorium on conducting in-person research and study enrollment until protocol changes to protect participant safety were approved and implemented. We detail the operational modifications made to the Lupus Intervention Fatigue Trial (LIFT) protocol and summarize how we met the varied challenges created by COVID-19., Methods: We evaluated study protocols and determined that scheduling, acquiring consent, in-person assessments and intervention baseline visits, patient reported outcomes, and data processing procedures needed modification., Results: Operational modifications were made to ensure study progress while adhering to COVID-19 restrictions. Major changes included electronic consent, remote baseline visits for those in the intervention, self-report outcome measures at home via emailed weblinks, and telemedicine physician assessment visits. The collection of safety labs presented the largest challenge since this required an in-person visit to a laboratory. The study team elected to delay this up to one month after the physician assessment. All follow-up visits were completed, and no participants withdrew from the study., Conclusion: LIFT was severely impacted by COVID-19. We provide insight into how our study protocol was modified without compromising the integrity of the primary and secondary outcomes of the study. The modifications utilized by the LIFT study resulted in efficiencies that will be included in a revised protocol and may serve as a useful example for other behavioral interventions to adapt their research studies., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: DKH, RRG, JSC, AY, LB, AC, DE, HM, AK, and LR have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. LEJ would like to disclose consulting work with Zimmer Biomet for training of Community Health Workers in motivational interviewing for a project to increase physical activity in disadvantaged populations of women with osteoarthritis., (Published by Elsevier Inc.)

Objective: Examine associations of hip abductor strength with (1) cartilage damage worsening in the tibiofemoral and patellofemoral compartments 2 years later, and (2) poor function and disability outcomes 5 years later., Methods: Participants had knee osteoarthritis (K/L ≥ 2) in at least one knee. Hip abductor strength was measured using Biodex Dynamometry. Participants underwent 3.0T MRI of both knees at baseline and 2 years later. Baseline-to-2-year cartilage damage progression, defined as any worsening of WORMS cartilage damage score, was assessed at each tibiofemoral and patellofemoral surface. LLFDI (Late-Life Function and Disability Instrument) and Chair-Stand-Rate were recorded at baseline and 5-year follow-up; outcomes analyzed using quintiles. Poor outcomes were defined as remaining in the same low-function quintiles or being in a worse quintile at 5-year follow-up. We analyzed associations of baseline hip abductor strength with cartilage damage worsening and function and disability outcomes using multivariable log-binomial models., Results: 275 knees from 164 persons [age = 63.7 (SD = 9.8) years, 79.3% women] comprised the structural outcome sample, and 187 persons [age = 64.2 (9.7), 78.6% women] the function and disability outcomes sample. Greater baseline hip abductor strength was associated with reduced risks of baseline-to-2-year medial patellofemoral and lateral tibiofemoral cartilage damage worsening [adjusted relative risks (RRs) range: 0.80-0.83) and with reduced risks of baseline-to-5-year poor outcomes for Chair-Stand-Rate and LLFDI Basic Lower-Extremity Function and Disability Limitation (adjusted RRs range: 0.91-0.94)., Conclusion: Findings support a beneficial role of hip abductor strength for disease modification and for function and disability outcomes, and as a potential therapeutic target in managing knee osteoarthritis., (Copyright © 2019 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objective: Among high risk individuals, whether knee lesions in tissues involved in osteoarthritis (OA) can improve prediction of knee OA is unclear. We hypothesized that models predicting (1) incident osteophytes and (2) incident osteophytes and joint space narrowing can be improved by including symptoms or function, and further improved by lesion status., Design: In Osteoarthritis Initiative (OAI) participants with normal knee X-rays, we assessed cartilage damage, bone marrow lesions (BMLs), and menisci. Cox proportional hazards models were used to develop risk prediction models for risk of each outcome. Nested models (increasingly larger baseline covariable sets) were compared using likelihood ratio tests and Schwarz Bayesian Information Criterion (SBC). Model discrimination used receiver operating characteristic (ROC) curves and area under the curve (AUC)., Results: In 841 participants [age 59.6, body mass index (BMI) 26.7, 55.9% women] over up to 7 years follow-up, each larger set improved prediction (+hand OA, injury, surgery, activities; +symptoms/function). Prediction was further improved by including cartilage damage both compartments, BMLs both compartments, meniscal tear, meniscal extrusion, sum of lesion types, number of subregions with cartilage damage, number of subregions with BMLs, and (concurrently) subregion number with cartilage damage, subregion number with BMLs, and meniscal tear. AUCs were ≥0.80 for both outcomes for number of subregions with cartilage damage and the combined model., Conclusions: Among persons at higher risk for knee OA with normal X-rays, MRI tissue lesions improved prediction of mild as well as moderate disease. These findings support that disease onset is likely occurring during the "high-risk" period and encourage a reorientation of approach., (Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)