Comparison of multistate Markov modeling with contemporary outcomes in a reanalysis of the NINDS tissue plasminogen activator for acute ischemic stroke treatment trial

Risk factors for stroke-related functional disability and mortality at Felege Hiwot Referral Hospital, Ethiopia

BACKGROUND

Stroke is one of the top causes of functional disability around the world. The main objective was to identify stroke-related functional outcomes and risk factors. A good functional outcome is defined as the absence of problems secondary to the stroke event, a poor functional outcome as the presence of complications, and mortality as the existence of complications.

METHOD

A retrospective cohort analysis was used to observe factors in 298 eligible adult (18 or older) stroke patients who attend outpatient clinics every three months at Felege Hiwot Referral Hospital between September 2019 and August 2021 to predict outcomes.

RESULT

The likelihood of dying from a poor outcome was 9%, and the likelihood of recovering was 24%. The average time spent on good and poor outcomes for different levels of independent variables varies according to their risk. During the first three years of follow-up, the instantaneous risk with a 95% confidence interval of transitioning from good to poor outcome in the women, aged 60 or older, with hypertension, atrial fibrillation, and hemorrhage stroke versus men stroke patients, aged 18 to 59, without hypertension, atrial fibrillation, and ischemic stroke were 1.54 (1.10, 2.15), 1.73 (1.19, 2.52), 2.34 (1.55, 3.53), 2.74 (1.64, 4.56), and 1.52 (1.10, 2.19) respectively. The hazard ratio of transitioning from poor outcome to death for patients with diabetes mellitus and atrial fibrillation versus those without diabetes mellitus and atrial fibrillation was estimated to be 1.95 (1.10, 3.46) and 3.39 (1.67, 6.89), respectively.

CONCLUSION

Women over 60 with hypertension, atrial fibrillation, and hemorrhagic stroke were more likely to progress from a good to a poor outcome. Diabetes and atrial fibrillation were also risk factors for progressing from a poor outcome to death. The states and transitions, as well as a clinical control of the hazards for the transition through states, should improve the physician's decision-making process. Since gender and age are difficult to control, early intervention by patients and the hospital may be critical in influencing functional outcomes.

Cost-effectiveness of seven-days-per-week rehabilitation schedule for acute stroke patients

BACKGROUND

Rehabilitation is an essential medical service for patients who have suffered acute stroke. Although the effectiveness of 7-days-per-week rehabilitation schedule has been studied in comparison with 5- or 6-days-per-week rehabilitation schedule, its cost-effectiveness has not been analyzed. In this research, to help formulate more cost-effective medical treatments for acute stroke patients, we analyzed the cost-effectiveness of 7-days-per-week rehabilitation for acute stroke from public health payer's perspective, and public healthcare and long-term care payer's perspective in Japan.

METHODS

Cost-effectiveness of 7-days-per-week rehabilitation for acute stroke patients was analyzed based on the result from a previous study using a Japanese database examining the efficacy of 7-days-per-week rehabilitation. Cost utility analysis was conducted by comparing 7-days-per-week rehabilitation with 5- or 6-days-per-week rehabilitation, with its main outcome incremental cost-effectiveness ratio (ICER) calculated by dividing estimated incremental medical and long-term care costs by incremental quality-adjusted life years (QALY). The costs were estimated using the Japanese fee table and from published sources. The time horizon was 5 years, and Markov modeling was used for the analysis.

RESULTS

The ICER was $6339/QALY from public health payer's perspective, lower than 5,000,000 Yen/QALY (approximately US$37,913), which was the willingness-to-pay used for the cost-effectiveness evaluation in Japan. The 7-day-per-week rehabilitation was dominant from public healthcare and long-term care payer's perspective. The result of sensitivity analysis confirmed the results.

CONCLUSION

The results indicated that 7-days-per-week rehabilitation for acute stroke rehabilitation was likely to be cost-effective.

Repeated Measures of Modified Rankin Scale Scores to Assess Functional Recovery From Stroke: AFFINITY Study Findings

Background

Function after acute stroke using the modified Rankin Scale (mRS) is usually assessed at a point in time. The analytical implications of serial mRS measurements to evaluate functional recovery over time is not completely understood. We compare repeated‐measures and single‐measure analyses of the mRS from a randomized clinical trial.

Methods and Results

Serial mRS data from AFFINITY (Assessment of Fluoxetine in Stroke Recovery), a double‐blind placebo randomized clinical trial of fluoxetine following stroke (n=1280) were analyzed to identify demographic and clinical associations with functional recovery (reduction in mRS) over 12 months. Associations were identified using single‐measure (day 365) and repeated‐measures (days 28, 90, 180, and 365) partial proportional odds logistic regression. Ninety‐five percent of participants experienced a reduction in mRS after 12 months. Functional recovery was associated with age at stroke <70 years; no prestroke history of diabetes, coronary heart disease, or ischemic stroke; prestroke history of depression, a relationship partner, living with others, independence, or paid employment; no fluoxetine intervention; ischemic stroke (compared with hemorrhagic); stroke treatment in Vietnam (compared with Australia or New Zealand); longer time since current stroke; and lower baseline National Institutes of Health Stroke Scale & Patient Health Questionnaire‐9 scores. Direction of associations was largely concordant between single‐measure and repeated‐measures models. Association strength and variance was generally smaller in the repeated‐measures model compared with the single‐measure model.

Conclusions

Repeated‐measures may improve trial precision in identifying trial associations and effects. Further repeated‐measures stroke analyses are required to prove methodological value.

Registration

URL: http://www.anzctr.org.au; Unique identifier: ACTRN12611000774921.

Treatment effect on ordinal functional outcome using piecewise multistate Markov model with unobservable baseline: an application to the modified Rankin scale

In clinical trials, longitudinally assessed ordinal outcomes are commonly dichotomized and only the final measure is used for primary analysis, partly for ease of clinical interpretation. Dichotomization of the ordinal scale and failure to utilize the repeated measures can reduce statistical power. Additionally, in certain emergent settings, the same measure cannot be assessed at baseline prior to treatment. For such a data set, a piecewise-constant multistate Markov model that incorporates a latent model for the unobserved baseline measure is proposed. These models can be useful in analyzing disease history data and are advantageous in clinical applications where a disease process naturally moves through increasing stages of severity. Two examples are provided using acute stroke clinical trials data. Conclusions drawn in this article are consistent with those from the primary analysis for treatment effect in both of the motivating examples. Use of these models allows for a more refined examination of treatment effect and describes the movement between health states from baseline to follow-up visits which may provide more clinical insight into the treatment effect.