Trajectories of depressive and anxiety symptoms and associated risk factors during the COVID-19 pandemic in Germany: A longitudinal cohort study.

BACKGROUND: Most COVID-19-related mental health research focused on average levels of mental health parameters in the general population. However, considering heterogeneous groups and their long-term responses could deepen our understanding of mental health during community crises. This four-wave study aimed to (1) identify subgroups with different trajectories of depressive and anxiety symptoms in the German general population, and (2) investigate associated risk factors. METHODS: We analyzed self-report data from N = 1257 German adults participating in a European cohort study, assessed in summer 2020 (T1), and at 6 (T2), 12 (T3), and 30 months (T4). Depressive and anxiety symptoms were measured using the PHQ-4. Sociodemographic, health-related, and pandemic-related variables were assessed at baseline. We applied growth mixture modeling to identify subgroups of symptom trajectories and conducted multinomial logistic regression to examine factors associated with class membership. RESULTS: We identified six symptom trajectories: Low-stable (n = 971, 77.2 %), Continuous deterioration (n = 30, 2.4 %), Transient deterioration (n = 75, 6.0 %), Continuous improvement (n = 97, 7.7 %), Transient improvement (n = 38, 3.0 %) and Chronicity (n = 46, 3.7 %). Age, education, work status, mental health diagnoses, self-reported health, and pandemic-related news consumption were significantly associated with subgroup membership. LIMITATIONS: The generalizability of the study is constrained by an unrepresentative sampling method, a notable dropout rate, and limited consideration of risk factors. CONCLUSION: Most people experienced low symptoms or improvement during the pandemic, while others experienced chronic or transient symptoms. Specific risk factors were associated with these trajectories, revealing nuanced mental health dynamics.

A rapid radiochemical purity testing method for 99mTc-tetrofosmin.

UNLABELLED: The standard radiochemical purity (RCP) testing method for (99m)Tc-tetrofosmin as described in the package insert requires extensive time (20-30 min) and considerable skill to achieve accurate results. Additionally, the instant thin-layer chromatography strip impregnated with silica gel (2x20 cm) used in the standard method will not be commercially available in the future. The purpose of this study was to evaluate whether a method developed by our laboratory for RCP testing of (99m)Tc-sestamibi could also be used as an alternative method for the RCP assay of (99m)Tc-tetrofosmin. METHODS: The alternative RCP testing system consisted of a precut paper strip (1x8.5 cm) from solvent saturation pads (Pall Corp.) as the stationary phase, with 1:1 chloroform:tetrahydrofuran used as the mobile phase. To validate the reliability of the alternative method, RCP values from 17 kit preparations were compared with the 2 methods. Kits were reconstituted according to the package insert instructions, and 4 additions of (99m)Tc-sodium pertechnetate were purposely added to create trials with RCP values below the accepted limit of 90% purity. RESULTS: Two hundred four trials (100 of which were replicated) were run from the 17 kit preparations. Sixty-four (31%) of the 204 trials were below 90% purity based on the standard method. The overall agreement between the standard and alternative methods was 94% (192/204). The sensitivity of the alternative method for unacceptable RCP limits was 86% (55/64), and the specificity for acceptable RCP values was 98% (137/140). The agreement between the replicated trials of the alternative method was 99% (99/100), and for the standard method it was 92% (92/100). CONCLUSION: The standard method proved to be a much slower method and requires much more precision and attention. The alternative method is much faster, is easier, requires less attention to the solvent-development process, and can be used for RCP testing of both (99m)Tc-tetrofosmin and (99m)Tc-sestamibi. Furthermore, the stationary phase is much more readily available, is not moisture-sensitive, and is less susceptible to operator technique. Our method is accurate in determining the RCP value of (99m)Tc-tetrofosmin and is a better RCP testing method for (99m)Tc-tetrofosmin.