Doctoral Thesis
Refine
Document Type
- Doctoral Thesis (2) (remove)
Language
- English (2) (remove)
Has Fulltext
- yes (2)
Is part of the Bibliography
- no (2)
Keywords
- Screening (2) (remove)
Institute
Background: To reduce the burden of disease attributable to alcohol, screening for at-risk alcohol use in the general population is recommended. Screening is usually carried out at only one point in time although individual alcohol use may change over time and self-reported consumption may be biased by underreporting. However, there are gaps in research on temporal variability of alcohol use. Therefore, this cumulative dissertation investigated (1) changes in drinking patterns within 4 weeks; (2) changes in screening results within 12 months and factors predicting a transition from low-risk to at-risk alcohol use; (3) whether underreporting can be reduced by prompting respondents to recall their alcohol use in the past week prior to screening.
Methods: Participants were adults from the general population recruited in a municipal registry office. For the first paper, 288 alcohol users were assessed four times using Timeline Follow-Back, each one week apart. Changes in drinking patterns were analyzed using latent transition modeling. For the second paper, 831 control group participants of a randomized controlled trial were screened for at-risk alcohol use at baseline, 3, 6, and 12 months later using the Alcohol Use Disorders Identification Test - Consumption (AUDIT-C). The transition from low-risk to at-risk alcohol use was predicted using logistic regression. For the third paper, 2,379 alcohol users were screened for at-risk alcohol use using the AUDIT-C, either before or after receiving the prompt to recall their past week alcohol use. Data were analyzed using logistic regression.
Results: Within 4 weeks, 35 percent of alcohol users changed their drinking pattern. Changes were more likely for individuals with moderate or heavy compared to light drinking. Within 12 months, 30 percent of alcohol users changed their screening result. Changes were more likely for at-risk compared to low-risk alcohol users. Transitioning from low-risk to at-risk alcohol use was more likely for women (vs. men; Odds Ratio, OR = 1.66), 18- to 29-year-old adults (vs. 30- to 45-year-old adults; OR = 2.30), and individuals reporting two or more drinking days in the past week (vs. less than two; OR = 3.11). When respondents were prompted to recall their alcohol use in the past week prior to screening, they were less likely to report at-risk alcohol use compared to when the screening was conducted without prior prompt (OR = 0.83).
Conclusions: One in three alcohol users changed their consumption, some of them even within a period as short as 4 weeks. These changes might compromise the validity of screening that is commonly based on a single assessment of typical alcohol use. Furthermore, underreporting cannot be reduced by prompting individuals to recall their alcohol use in the past week prior to the screening for at-risk alcohol use. Rather, consecutive questionnaires addressing different aspects of alcohol use within a single survey might be a potential source of bias.
This thesis is about the establishment and the application of novel methods and tools that are re-lated to the most widely used enzyme class: hydrolases. It covers all fields from the identification to the application of these valuable enzymes with particular focus on lactonases, acylases and proteases. The activity assay introduced in Article I substantially extends the method toolbox for studies on lactonases and acylases that interfere with the bacterial cell-cell communication system. Article II describes a fully automatized robotic platform that represents the next-level tool for the high-throughput enzyme screening in the microtiter plate format. It was used, for instance, for the screening for improved porcine aminoacylase I variants. Diverse aspects of the protease-mediated hydrolysis of non-resistant proteins for the purification of resistant target proteins are highlighted in Article III.