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1. Ethical approval and regulatory compliance
This study was conducted as a hospital-based quality-improvement and operational evaluation initiative within the Department of Stomatology at Guigang People’s Hospital. Ethical approval was obtained from the Ethics Committee of Guigang People’s Hospital (Approval No. GGPH-2022-061; approved December 15, 2022). The ethics committee approved the analysis of dispensing, inventory management, and logistics system data extracted from institutional information systems. Because no identifiable patient information was collected, informed consent from individual patients was waived. Staff workload and service-satisfaction surveys were conducted voluntarily and anonymously. Completion of the questionnaire was considered implied consent to participate. Survey responses were aggregated prior to analysis, and no personally identifiable information was collected. The workload and satisfaction questionnaires were developed using routine departmental operational indicators for the evaluation of consumables management. Questionnaire items were reviewed by departmental supervisors and pilot-tested for clarity and feasibility before implementation. The research tools used in this protocol are listed in the Table of Materials.
2. Study design and reporting framework
This single-center quasi-experimental pre–post study evaluated the implementation of a hospital-operated Supply–Processing–Distribution (SPD) logistics management model for medical consumables in the Department of Stomatology at Guigang People’s Hospital (Guangxi, China). The pre-implementation period extended from January 1, 2023, to June 30, 2023, and the post-implementation period extended from July 1, 2023, to December 31, 2023. The SPD system became operational on July 1, 2023. The study therefore included 52 weeks of observation, comprising 26 pre-implementation and 26 post-implementation weeks.
This quality-improvement study was reported according to the Standards for Quality Improvement Reporting Excellence (SQUIRE 2.0) guidelines6 and, where applicable, the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations7. Interrupted time-series (ITS) segmented regression was prespecified for outcomes with monthly aggregation and sufficient longitudinal observations (≥12 total time points)8. ITS analysis was selected because the intervention occurred at a clearly defined institutional implementation point and because the method is appropriate for evaluating longitudinal operational interventions in real-world healthcare settings.
3. Setting
The study was conducted in the Department of Stomatology of a tertiary hospital with approximately 2,400 outpatient visits and 180 minor dental procedures per month. Consumables included routinely used clinical and procedural items managed through the SPD system during the study period, including disposable dental materials, diagnostic consumables, treatment-support items, and temperature-sensitive consumables requiring monitored storage conditions.
Before SPD implementation, consumables management relied on an incomplete hospital information system (HIS), decentralized stock-holding locations, manual requisition procedures, spreadsheet-assisted inventory reconciliation, and manually performed periodic inventory counts.
4. Intervention: Hospital-operated SPD logistics model
The intervention consisted of implementation of a hospital-operated SPD logistics-management model integrating software infrastructure, barcode-enabled hardware systems, and operational-governance workflows.
An SPD implementation team was established, consisting of one project lead, two procurement officers, two warehouse managers, one information-technology engineer, and one quality supervisor. Standardized item master-data parameters—including unique item identifiers, supplier information, pricing, storage requirements, expiration parameters, and barcode encoding—were configured within the SPD platform.
Bidirectional synchronization between the SPD system and the HIS was implemented to enable real-time synchronization of requisitions, inventory movement records, dispensing documentation, and billing reconciliation.
Barcode-enabled smart storage cabinets were installed in clinical areas to support automated stock reduction during consumable dispensing. Relevant staff received standardized workflow training before implementation. Compliance with SPD workflows was monitored through routine departmental supervision and system-based traceability procedures.
Temperature-sensitive consumables were stored in monitored refrigeration units in accordance with institutional storage requirements. Refrigeration temperatures were routinely monitored to maintain recommended storage ranges, and deviations were managed in accordance with departmental consumables governance protocols.
Role-based access control (RBAC) was implemented to restrict access to the SPD system to authorized personnel. Before system activation, two complete-cycle simulation tests were conducted, including requisition submission, inventory receipt, consumable dispensing, billing reconciliation, and item returns. All personnel received role-specific training before the system went live. Daily operational briefings were conducted during the first two weeks after implementation to address technical and workflow issues.
For this study, delivery error was defined as any discrepancy between requested and delivered consumables, including mismatches in quantity, specification, or item type. Irrational usage refers to consumable utilization inconsistent with departmental consumption standards or clinical indications. Integrity incidents included compromised packaging, incomplete documentation, and failures in consumable traceability. Dispensing anomalies were defined as irregularities during the dispensing process, including mismatched items, missing items, or documentation discrepancies.
5. Data sources and eligibility criteria
Staff workload and service satisfaction were evaluated using weekly surveys administered to all personnel involved in consumables management within the Department of Stomatology (N = 18). Surveys were conducted throughout the 52-week observation period.
The maximum number of survey observations was 468 per study period (18 staff × 26 weeks). During the pre-implementation phase, 448 of 468 questionnaires were completed (95.7%), compared with 452 of 468 questionnaires (96.6%) during the post-implementation phase.
Staff workload was assessed using structured weekly time logs documenting hours spent on consumables-related activities, including requisition preparation, stock receiving, manual reconciliation, expiration management, and administrative documentation. Weekly workload was calculated as the mean number of hours per week across responding staff.
Delivery error rate was calculated using the following equation:
Delivery Error Rate (%) = (Number of Erroneous Dispensing Events ÷ Total Dispensing Events) × 100
Service satisfaction was evaluated using a five-item questionnaire scored on a 0–100 scale that assessed delivery timeliness, dispensing accuracy, product availability, requisition-workflow convenience, and overall consumables management satisfaction. Weekly satisfaction scores were calculated as the mean completed-item score.
Because repeated measurements were obtained from the same personnel, workload, and satisfaction outcomes were aggregated at the weekly level before statistical analysis to avoid treating repeated responses as independent observations.
6. Statistical analysis
All statistical analyses were performed using R software (version 4.3.1). Continuous variables were reported as mean ± standard deviation or median and interquartile range, as appropriate. Categorical variables were summarized using frequencies and percentages.
When normality assumptions were satisfied, paired t-tests were used to compare continuous outcomes before and after implementation. Otherwise, Wilcoxon signed-rank tests were applied. Two-proportion z-tests or Fisher’s exact tests were used for proportional outcomes, depending on expected cell counts.
Multivariable regression analyses were prespecified to adjust for potential confounding variables. Linear regression models were used to evaluate weekly mean delivery time, with implementation status as the primary independent variable and weekly consumable volume and clinical-visit frequency included as covariates. Logistic regression models were used to evaluate delivery-error events, adjusting for implementation status, weekly consumable volume, and item category. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were reported.
For outcomes with monthly aggregation and sufficient time points, interrupted time-series segmented regression analysis was performed using the following model:
Yt = β0 + β1(Timet) + β2(Interventiont) + β3(Time After Interventiont) + εt
Where Yt represents the outcome at time point t; Timet represents the continuous time sequence; Interventiont represents the pre-implementation (0) and post-implementation (1) periods; Time After Interventiont represents elapsed time after SPD implementation; and εt represents the error term.
Autocorrelation was evaluated using the Durbin–Watson statistic, and Newey–West standard errors were applied when autocorrelation was detected. Statistical significance was defined as a two-sided p-value < 0.05. For segmented regression analyses, regression coefficients (β), standard errors (SEs), and 95% confidence intervals (CIs) were reported for both immediate level changes (β2) and post-intervention slope changes (β3).