"Vitamin C Deficiency in Hospitalized Adults: Systematic Screening Vs. Traditional Judgment - a Before-and-After Observational Study"

Study Design and Methodology

Study Type:

Observational (before-after study design)

Retrospective for the control group (patients with historical vitamin C measurements) and for exposure group (patients systematically screened based on predefined hemorrhagic criteria)

Study Population:

Inclusion Criteria:

Adults (age ≥18 years) admitted to the hospital

Presence of micro- or macroscopic hemorrhagic symptoms

Undergoing vitamin C level assessment (either systematic or based on physician discretion)

Exclusion Criteria:

Refusal to participate

Prior vitamin C supplementation within one month before the study period

Study Groups:

Control Group (Retrospective):

Patients with documented hemorrhagic symptoms for whom vitamin C levels were measured based on physician judgment (prior to implementation of systematic screening criteria).

Exposure Group (Prospective):

Patients identified through a systematic screening protocol incorporating predefined hemorrhagic criteria.

Primary Outcome:

Incidence of vitamin C deficiency (defined as serum ascorbic acid levels below laboratory reference ranges) in patients with hemorrhagic symptoms.

Secondary Outcomes:

Diagnostic efficiency of the systematic screening approach versus traditional physician-led assessment.

Association between vitamin C deficiency and anemia (hemoglobin levels, mean corpuscular volume, ferritin, reticulocyte count, transferrin saturation).

Association with other micronutrient deficiencies (folate, B12, albumin, and iron status).

Presence of concurrent infections in vitamin C-deficient patients.

Impact on hospital length of stay in vitamin C-deficient patients versus non-deficient patients.

Data Collection and Registry Procedures

Quality Assurance Plan:

Data validation and registry procedures include automated and manual data checks for completeness and consistency.

On-site data audits will be conducted to ensure compliance with study protocols.

Standardized case report forms (CRFs) will be used for data collection.

Data Verification and Source Validation:

Data consistency checks will compare registry entries with patient medical records.

Laboratory values will be cross-validated against hospital electronic records.

External source verification will be conducted for select cases to assess data accuracy.

Standard Operating Procedures (SOPs):

Patient Recruitment: Patients meeting inclusion criteria will be identified through hospital electronic records and physician referrals.

Data Collection:

Baseline assessment will include demographic details, medical history, and medication use (e.g., anticoagulants, nutritional supplements).

Clinical evaluation will include hemorrhagic symptoms (ecchymosis, petechiae, gastrointestinal bleeding, hematuria, epistaxis).

Laboratory assessments will include vitamin C levels, hemoglobin, ferritin, folate, B12, albumin, and markers of infection.

Data Management:

De-identified patient data will be stored in a secure, access-controlled database.

Routine data audits will ensure quality and completeness.

Statistical Analysis:

Data will be analyzed per predefined statistical models to assess prevalence and associations.

Sample Size Assessment:

Estimated 42 patients per group based on prevalence estimates of 20% vitamin C deficiency in hospitalized patients with hemorrhagic symptoms.

Sample size determination accounts for a power of 80% and alpha of 0.05.

Bayesian inference will be applied if sample size calculations require adjustments based on interim analyses.

Plan for Handling Missing Data:

Imputation methods (multiple imputations) will be used for missing laboratory values.

Sensitivity analyses will assess the impact of missing data on study conclusions.

Statistical Analysis Plan:

Descriptive Statistics:

Mean, median, standard deviation for continuous variables.

Frequency distribution for categorical variables.

Comparative Analyses:

Student's t-test or Mann-Whitney U test for continuous variables.

Chi-square or Fisher's exact test for categorical variables.

Multivariable Regression Models:

Adjustments for confounders (age, comorbidities, nutritional status, anticoagulant use).

Logistic regression for risk factor analysis of vitamin C deficiency.

Cox proportional hazards model for hospital length of stay impact analysis.

Sensitivity Analyses:

Assess variations in vitamin C deficiency prevalence.

Evaluate changes in detection efficiency of systematic screening protocol.

Ethical Considerations

The study is non-interventional and does not alter clinical care.

Patient confidentiality will be ensured through anonymized data collection and secure storage.

Informed consent will be obtained for prospective participants.

The study has received ethical approval from the Centre Hospitalier de Guéret Ethics Committee.

Data Dissemination Plan

Results will be published in peer-reviewed medical journals.

Findings will be shared with hospital medical teams to optimize patient care.

A summary report will be provided to participants upon study completion.

Conclusion

This study will provide critical insights into the prevalence of vitamin C deficiency in hospitalized patients with hemorrhagic symptoms. By evaluating a structured screening approach, this research aims to improve early detection and clinical awareness of vitamin C deficiency, potentially informing future guidelines for at-risk populations.