Joint modeling of longitudinal CD4 count data and time to first occurrence of composite outcome

In this study, we jointly modeled longitudinal CD4 count data and survival outcome (time-to-first occurrence of composite outcome of death, cardiac tamponade or constriction) in other to investigate the effects of Mycobacterium indicus pranii immunotherapy and the CD4 count measurements on the hazard of the composite outcome among patients with HIV and tuberculous (TB) pericarditis. In this joint modeling framework, the models for longitudinal and the survival data are linked by an association structure. The association structure represents the hazard of the event for 1-unit increase in the longitudinal measurement. Models fitting and parameter estimation were carried out using R version 4.2.3. The association structure that represents the strength of the association between the hazard for an event at time point j and the area under the longitudinal trajectory up to the same time j provides the best fit. We found that 1-unit increase in CD4 count results in 2 % significant reduction in the hazard of the composite outcome. Among HIV and TB pericarditis individuals, the hazard of the composite outcome does not differ between of M.indicus pranii versus placebo. Application of joint models to investigate the effect of M.indicus pranii on the hazard of the composite outcome is limited. Hence, this study provides information on the effect of M.indicus pranii on the hazard of the composite outcome among HIV and TB pericarditis patients.

Determining whether periodic health checkups have any preventive effect on deterioration in health among middle-aged adults: A hazards model analysis in Japan

OBJECTIVES

We aimed to examine the long-term impact of periodic health checkups (PHCs) on health outcomes among middle-aged adults.

METHODS

We used longitudinal data from 29 770 individuals (15 399 men and 14 371 women) aged 50-59 years in the baseline year (2005), obtained from a population-based 14-wave survey. PHC participants were defined as those who underwent PHCs for the first three consecutive waves, and we investigated the onset of inpatient care for five types of non-communicable diseases (diabetes, heart disease, stroke, hypertension, and dyslipidemia) as well as poor self-rated health and problems in the activities of daily living in the subsequent 11 waves. Cox-proportional hazards models were used to estimate the impact of PHCs on health outcomes by employing the propensity score matching (PSM) method.

RESULTS

Participation in PHCs was closely related to a respondent's socioeconomic status and health behavior. After controlling for these factors by PSM, the hazard models showed that PHCs postponed the onset of inpatient care for hypertension (hazard ratio, 0.56; 95% confidence interval: 0.36-0.85) among men, but PHCs had no impact on any other health outcomes in men or women.

CONCLUSIONS

The preventive impact of PHCs on health deterioration is generally limited among middle-aged adults. Future studies should address policy measures to enhance the effectiveness of PHCs.