27  Appendix

27.1 Supplementary Tables

27.1.1 Complete Pathologist Consultation Matrix

Complete Consultation Matrix (Asker vs Responder)
Asker P10 P11 P15 P16 P17 P18 P2 P21 P23 P24 P3 P33 P4 P5 P6 P8 P9 P1 P13 P19 P20 P25 P27 P28 P32 P22 P14 P7 P26 P29 P30 P12
P1 14 3 1 1 24 1 17 3 25 1 1 4 1 15 1 14 32 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
P10 0 10 0 0 56 1 26 197 3 0 0 6 1 13 3 14 12 5 6 60 1 1 14 4 1 0 0 0 0 0 0 0
P11 2 0 0 3 3 4 12 2 13 0 0 5 3 21 27 16 48 0 5 3 0 1 2 1 0 0 0 0 0 0 0 0
P12 0 0 0 0 2 0 1 0 0 0 0 0 0 1 1 1 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0
P13 18 154 0 2 23 1 74 21 34 54 0 5 1 87 19 73 48 0 0 49 0 0 2 16 1 2 0 0 0 0 0 0
P14 0 1 0 9 9 2 22 0 0 0 1 11 0 35 3 0 35 2 0 9 0 0 0 0 0 0 0 0 0 0 0 0
P15 0 0 0 1 2 1 3 0 0 0 0 9 0 3 2 2 8 0 0 4 0 0 0 0 0 0 1 1 0 0 0 0
P16 0 7 0 0 0 5 9 14 7 0 0 0 6 19 1 1 30 0 2 4 0 1 3 2 0 0 0 0 0 0 0 0
P17 2 2 0 1 0 3 62 12 11 1 0 22 0 50 2 14 2 0 3 18 0 0 0 0 0 0 0 0 2 0 0 0
P18 11 35 0 2 6 0 14 16 37 0 2 7 28 35 17 10 58 2 1 1 0 3 9 21 1 0 0 1 0 1 1 0
P19 16 1 0 0 10 6 10 4 0 4 0 4 2 34 1 4 8 0 10 0 0 0 16 0 0 0 0 1 0 0 0 0
P2 13 2 0 4 45 4 0 17 16 11 0 9 1 44 56 12 7 7 12 9 0 0 1 2 0 0 0 0 3 0 0 0
P20 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0
P21 74 6 0 19 16 1 27 0 8 1 0 1 0 16 0 10 2 0 8 2 0 0 1 4 0 0 0 0 0 0 1 0
P22 0 94 0 0 0 0 0 0 3 0 0 0 0 9 0 73 4 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0
P23 2 5 0 0 8 2 18 2 0 4 0 0 1 26 0 32 5 0 0 1 0 2 3 4 0 0 0 0 0 0 1 0
P24 0 0 0 0 6 0 52 4 5 0 0 0 0 20 0 13 30 0 0 6 0 0 4 0 0 0 0 0 0 0 0 0
P25 1 6 0 0 23 0 9 2 2 0 0 0 1 6 0 1 2 0 0 0 0 0 0 2 0 0 0 0 1 0 0 0
P26 0 4 0 1 1 0 22 1 2 0 0 0 1 6 0 0 12 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
P27 4 16 0 2 0 7 2 1 19 3 0 0 17 8 0 3 13 0 1 11 0 2 0 14 2 0 0 0 0 0 8 0
P28 10 25 0 1 2 4 5 24 25 1 0 0 4 104 0 6 20 0 2 0 0 2 2 0 2 0 0 0 0 0 2 0
P29 16 18 0 0 0 0 2 19 4 2 0 0 1 19 0 2 7 0 0 0 0 2 0 7 0 0 0 0 0 0 0 0
P3 0 0 0 9 5 3 21 0 0 0 0 104 0 14 9 6 38 7 0 9 0 0 0 0 0 0 2 0 0 0 0 1
P30 0 3 0 0 0 1 0 1 1 0 0 0 0 1 0 1 1 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0
P31 1 0 0 0 0 0 0 0 3 10 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0
P32 0 1 0 0 0 1 0 1 3 0 0 0 2 0 0 0 0 0 0 0 0 0 1 3 0 0 0 0 0 0 0 0
P4 12 46 0 1 4 18 6 24 24 3 2 14 0 21 44 13 51 3 3 12 1 1 28 8 1 0 1 0 0 0 4 0
P5 4 2 0 12 7 2 36 18 4 15 4 9 0 0 7 4 19 2 0 4 0 0 3 22 0 0 2 0 0 0 0 0
P6 1 2 0 1 0 1 53 0 0 0 1 2 1 23 0 10 36 0 1 4 0 0 0 0 0 0 0 0 0 0 0 0
P7 0 3 0 2 1 7 52 0 2 0 0 4 2 3 5 7 12 0 0 10 0 0 0 0 0 0 1 0 0 0 0 0
P8 9 41 0 0 105 1 106 10 142 3 0 41 3 87 36 0 155 0 3 5 0 0 1 6 0 0 0 0 0 0 0 0
P9 6 34 0 4 4 6 23 6 14 7 3 4 3 30 20 4 0 0 11 3 0 2 2 6 0 0 1 0 0 0 1 0
NA 0 1 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0

27.1.2 Detailed Monthly Statistics

Detailed Monthly Consultation Statistics
Month Total_Consultations Unique_Cases Unique_Askers Unique_Responders Min_TAT Q1_TAT Median_TAT Mean_TAT Q3_TAT Max_TAT SD_TAT Within_24h Pct_24h
2022-08-01 27 18 9 10 0.0 2.6 13.9 11.2 17.5 23.0 7.8 27 100.0
2022-09-01 59 49 14 11 0.4 3.4 14.2 13.0 17.5 103.1 14.6 57 96.6
2022-10-01 124 84 16 14 0.0 2.1 5.1 9.5 14.2 58.4 9.9 118 95.2
2022-11-01 192 107 16 14 0.1 3.2 14.2 13.0 17.5 96.9 13.4 177 92.2
2022-12-01 197 117 18 14 0.0 2.1 5.1 8.5 14.2 67.3 9.4 191 97.0
2023-01-01 208 128 18 15 0.0 2.1 5.1 10.3 17.5 96.1 14.7 193 92.8
2023-02-01 96 73 16 13 0.0 0.6 4.0 13.8 17.5 97.1 21.2 80 83.3
2023-03-01 119 84 14 13 0.0 0.9 4.7 16.4 20.1 99.3 23.5 91 76.5
2023-04-01 77 58 14 14 0.0 1.1 5.1 17.0 25.3 97.1 23.4 57 74.0
2023-05-01 96 75 17 12 0.0 1.0 5.3 14.4 19.3 97.5 21.3 82 85.4
2023-06-01 77 65 14 10 0.0 0.9 4.7 15.8 17.3 99.3 23.4 63 81.8
2023-07-01 87 65 16 13 0.0 1.2 3.7 12.8 12.0 92.5 20.7 72 82.8
2023-08-01 119 89 15 12 0.0 1.2 5.1 14.8 21.0 93.3 19.6 96 80.7
2023-09-01 90 69 17 14 0.0 0.9 5.1 16.4 21.9 97.9 24.0 69 76.7
2023-10-01 66 59 15 10 0.0 0.8 2.9 14.8 20.9 93.5 22.7 52 78.8
2023-11-01 85 68 17 13 0.0 0.7 3.5 17.1 23.5 103.5 24.4 65 76.5
2023-12-01 86 75 15 13 0.0 1.1 4.8 13.1 20.7 88.1 18.3 68 79.1
2024-01-01 90 83 14 12 0.2 1.4 3.9 11.2 17.7 69.1 15.6 76 84.4
2024-02-01 123 101 17 15 0.0 1.4 3.9 14.8 18.1 97.1 21.7 105 85.4
2024-03-01 124 104 15 14 0.0 0.6 3.4 8.2 11.3 73.9 12.6 116 93.5
2024-04-01 79 69 15 13 0.0 1.0 3.4 13.4 18.7 94.1 21.2 66 83.5
2024-05-01 159 134 19 15 0.0 0.7 2.7 9.5 11.3 73.9 15.2 141 88.7
2024-06-01 124 101 18 15 0.0 1.1 2.9 11.0 16.0 81.2 16.1 106 85.5
2024-07-01 142 121 18 15 0.0 0.4 1.9 8.1 7.6 101.8 14.5 129 90.8
2024-08-01 118 110 18 14 0.0 0.9 4.3 12.5 18.1 74.4 16.6 99 83.9
2024-09-01 112 105 18 14 0.0 1.2 3.0 9.7 14.7 96.6 15.5 104 92.9
2024-10-01 169 146 18 16 0.0 0.8 2.3 9.6 11.1 68.7 15.4 147 87.0
2024-11-01 117 97 19 14 0.1 0.9 3.0 10.2 15.5 87.0 14.8 103 88.0
2024-12-01 161 140 19 14 0.0 0.8 2.7 10.2 16.1 96.3 16.0 143 88.8
2025-01-01 241 210 20 17 0.0 0.6 2.0 8.1 11.3 90.2 13.9 220 91.3
2025-02-01 203 170 21 18 0.0 0.7 2.4 7.4 8.5 83.9 11.6 184 90.6
2025-03-01 261 180 20 18 0.0 0.8 2.9 9.9 14.1 77.3 15.3 230 88.1
2025-04-01 199 144 20 18 0.0 0.7 1.8 7.8 8.3 85.2 13.3 183 92.0
2025-05-01 240 177 20 17 0.0 0.6 1.9 6.0 5.0 72.9 10.9 227 94.6
2025-06-01 195 141 19 18 0.0 0.6 2.4 7.4 7.9 101.9 12.8 181 92.8
2025-07-01 228 188 20 18 0.0 0.9 2.4 8.4 11.3 96.2 15.3 212 93.0
2025-08-01 192 151 20 17 0.0 0.9 2.7 7.9 9.0 69.4 12.6 177 92.2
2025-09-01 231 166 22 19 0.0 1.0 2.5 10.0 13.7 102.4 16.8 205 88.7
2025-10-01 234 175 23 19 0.0 0.9 2.6 9.0 12.5 95.2 14.2 209 89.3
2025-11-01 288 217 23 22 0.0 1.0 3.0 8.4 11.6 94.9 13.1 263 91.3
2025-12-01 47 30 14 17 0.1 0.6 1.8 5.3 4.4 40.2 8.5 43 91.5

27.1.3 Pathologist-Level Performance Details

Detailed Performance Statistics by Responder
Responder N Min Q1 Median Mean Q3 Max SD Within_24h Pct_24h Within_48h Pct_48h
P5 751 0.0 0.7 2.0 7.6 6.7 103.1 14.0 692 92.1 729 97.1
P9 696 0.0 2.0 5.1 10.1 11.5 96.3 14.2 623 89.5 668 96.0
P2 684 0.0 0.9 2.1 6.5 5.0 97.5 12.6 642 93.9 668 97.7
P11 522 0.0 0.7 1.7 5.4 4.2 70.5 9.7 501 96.0 516 98.9
P23 407 0.0 1.2 3.0 7.1 9.9 69.2 10.3 383 94.1 400 98.3
P21 399 0.0 1.3 3.7 12.3 19.8 90.2 16.6 340 85.2 382 95.7
P17 362 0.0 4.0 20.3 24.5 32.5 101.9 23.9 233 64.4 304 84.0
P8 348 0.0 1.1 3.4 11.7 15.1 102.4 19.6 298 85.6 323 92.8
P33 261 0.0 17.5 17.5 19.2 17.5 97.9 18.0 224 85.8 241 92.3
P6 254 0.0 1.4 14.2 17.9 17.4 103.5 21.5 203 79.9 226 89.0
P19 227 0.0 1.2 2.6 7.9 5.3 73.9 13.0 206 90.7 221 97.4
P10 216 0.0 0.6 1.4 6.8 4.8 81.2 12.9 202 93.5 211 97.7
P28 124 0.0 1.0 3.0 9.8 12.7 95.2 16.0 112 90.3 120 96.8
P24 120 0.0 0.1 1.3 5.1 3.8 87.0 11.7 114 95.0 118 98.3
P27 94 0.0 0.3 1.1 4.7 2.9 48.6 9.5 88 93.6 93 98.9
P18 83 0.0 0.7 4.0 8.5 11.3 83.9 13.3 75 90.4 81 97.6
P4 79 0.1 2.4 8.9 12.1 16.1 92.0 14.5 72 91.1 76 96.2
P16 75 0.0 3.2 18.1 18.5 23.6 85.2 18.4 56 74.7 68 90.7
P13 68 0.0 0.6 1.8 7.3 3.7 72.3 13.5 63 92.6 65 95.6
P1 29 0.0 2.7 13.9 15.0 13.9 95.8 18.3 27 93.1 28 96.6
P30 18 0.1 1.5 3.4 6.9 10.4 25.4 8.1 17 94.4 18 100.0
P25 17 0.3 0.6 6.1 11.2 20.3 40.0 12.5 15 88.2 17 100.0
P3 15 0.9 5.0 5.5 13.2 12.8 61.6 17.8 12 80.0 14 93.3
P14 8 0.4 0.5 0.5 0.5 0.5 0.5 0.0 8 100.0 8 100.0
P32 8 0.3 0.7 1.4 14.1 16.8 71.6 24.6 7 87.5 7 87.5
P26 6 0.0 3.2 9.8 22.9 40.2 66.5 27.9 4 66.7 4 66.7
P22 3 0.4 0.4 0.5 0.5 0.5 0.6 0.1 3 100.0 3 100.0
P7 3 1.0 4.1 7.2 7.2 10.3 13.4 6.2 3 100.0 3 100.0
P20 2 1.1 6.9 12.7 12.7 18.5 24.3 16.4 1 50.0 2 100.0
P12 1 1.6 1.6 1.6 1.6 1.6 1.6 NA 1 100.0 1 100.0
P15 1 1.6 1.6 1.6 1.6 1.6 1.6 NA 1 100.0 1 100.0
P29 1 0.1 0.1 0.1 0.1 0.1 0.1 NA 1 100.0 1 100.0

27.2 Statistical Test Details

27.2.1 Normality Tests

Normality Tests for Turnaround Time (sample of 5000)
Test Statistic P_Value Interpretation
Shapiro-Wilk 0.6496 <2e-16 Data significantly non-normal
Skewness 2.6880 Highly skewed
Kurtosis 11.2800 Heavy tails (leptokurtic)

27.2.2 Complete Statistical Test Results

Summary of Statistical Tests and Rationale
Research Question Test Used Reason for Test Choice Key Assumption
Volume vs TAT correlation Spearman correlation Non-normal data, monotonic relationship Monotonic relationship
Day of week effect on TAT Kruskal-Wallis H test Non-normal data, >2 groups Independent groups
Time of day effect on TAT Kruskal-Wallis H test Non-normal data, >2 groups Independent groups
Responder differences in TAT Kruskal-Wallis H test Non-normal data, >2 groups Independent groups
Number of consultants vs TAT Spearman correlation Non-normal data, monotonic relationship Monotonic relationship
Weekend vs weekday TAT Mann-Whitney U test Non-normal data, 2 groups Independent groups
Temporal trend in volume Adjusted Mann-Kendall trend test Time series trend detection Serial correlation/seasonality adjusted as needed

27.3 R Code for Key Analyses

27.3.1 Data Processing Code

Code
# Data processing example (from process_data.R)
library(readxl)
library(dplyr)
library(lubridate)
library(stringr)

# Read consultation data
# Read Primary Sources
df_paylasilan <- read_excel("data/Paylasilan Vakalar 2024.xlsx", skip=2)
df_vaka <- read_excel("data/2024_vaka_paylasildi.xlsx")
df_internal <- read_excel("data/2024_internal_consultation.xlsx")

# Prioritize Asker (Paylasilan > Internal > Vaka)
df_merged <- df_internal %>%
  left_join(df_paylasilan, by = "Case_ID") %>%
  left_join(df_vaka, by = "Case_ID") %>%
  mutate(
    Asker = coalesce(Asker_Paylasilan, Asker_Internal, Asker_Vaka),
    Start_Time = coalesce(Start_Time_Vaka, Start_Time_Internal),
    Responder = Responder_Internal,
    Completion_Time = Completion_Time_Internal
  )

# Join and calculate TAT
df_consultations <- df_vaka %>%
  inner_join(df_kalite, by = "Case_ID") %>%
  filter(Initiator != Responder) %>%
  filter(Completion_Time > Start_Time) %>%
  mutate(
    Turnaround_Time_Hours = as.numeric(
      difftime(Completion_Time, Start_Time, units = "hours")
    ),
    Turnaround_Time_Days = as.numeric(
      difftime(Completion_Time, Start_Time, units = "days")
    )
  )

27.3.2 Network Analysis Code

Code
library(igraph)

# Create network from consultation data
edges <- df %>%
  group_by(Asker, Responder) %>%
  summarise(Weight = n(), .groups = "drop")

# Create graph
network <- graph_from_data_frame(edges,
                                 directed = TRUE,
                                 vertices = unique(c(edges$Asker, edges$Responder)))

# Calculate centrality metrics
degree_in <- degree(network, mode = "in")
degree_out <- degree(network, mode = "out")
betweenness <- betweenness(network, directed = TRUE, weights = E(network)$Weight)
closeness <- closeness(network, mode = "all")
pagerank <- page_rank(network, weights = E(network)$Weight)$vector

# Community detection
communities <- cluster_louvain(network, weights = E(network)$Weight)

27.3.3 Predictive Modeling Code

Code
library(broom)

# Prepare features
df_model <- df %>%
  mutate(
    Hour = hour(Start_Time),
    DayOfWeek = wday(Start_Time, week_start = 1),
    IsWeekend = ifelse(DayOfWeek %in% c(6, 7), 1, 0),
    Month = month(Start_Time),
    Log_TAT = log(Turnaround_Time_Hours + 1)
  ) %>%
  group_by(Case_ID) %>%
  mutate(Case_Complexity = n()) %>%
  ungroup()

# Linear regression
model_lm <- lm(Log_TAT ~ IsWeekend + Hour + Month + Case_Complexity,
              data = df_model)

summary(model_lm)

# Logistic regression for fast response
df_model$Fast_Response <- ifelse(df_model$Turnaround_Time_Hours <= 24, 1, 0)

model_logistic <- glm(Fast_Response ~ IsWeekend + Hour + Month + Case_Complexity,
                     data = df_model,
                     family = binomial())

summary(model_logistic)

27.4 Glossary of Terms

Glossary of Technical Terms
Term Definition
Asker Pathologist who initiates a consultation request
Responder Pathologist who provides consultation response
Turnaround Time (TAT) Time between consultation request and completion
In-Degree Number of consultations received (incoming edges)
Out-Degree Number of consultations initiated (outgoing edges)
Betweenness Centrality Measure of how often a node lies on shortest paths between other nodes
PageRank Algorithm measuring importance based on link structure
Gini Coefficient Measure of inequality in distribution (0=perfect equality, 1=perfect inequality)
Community Detection Algorithmic identification of groups within a network
Network Density Proportion of actual connections to possible connections
Reciprocity Proportion of bidirectional relationships in network
Control Chart Statistical process control tool showing mean and control limits
Outlier Data point significantly different from others (typically >99th percentile)
KPI Key Performance Indicator - metric used to evaluate success
SLA Service Level Agreement - formal commitment to service standards
Triage Process of categorizing by urgency or priority

27.5 Software and Package Versions

Key R Package Versions Used
Package Version
dplyr 1.1.4
ggplot2 4.0.1
igraph 2.2.1
lubridate 1.9.4
knitr 1.51
kableExtra 1.4.0
broom 1.0.11
tidyr 1.3.2

R Version: R version 4.5.1 (2025-06-13)

Platform: aarch64-apple-darwin20

System: macOS Tahoe 26.2

27.6 Data Dictionary

Data Dictionary for Processed Dataset
Variable Type Description Valid Range / Values
Case_ID Character Unique identifier for pathology case (format: XXXXX-YY) Format varies by institution
Asker Character (Code) Anonymized code for pathologist requesting consultation (P1, P2, ...) P1 through P[N] where N = number of pathologists
Responder Character (Code) Anonymized code for pathologist providing consultation (P1, P2, ...) P1 through P[N] where N = number of pathologists
Start_Time POSIXct Timestamp when consultation was initiated (UTC) Within study period
Completion_Time POSIXct Timestamp when consultation was completed (UTC) After Start_Time, within study period
Turnaround_Time_Hours Numeric Duration of consultation in hours > 0
Turnaround_Time_Days Numeric Duration of consultation in days > 0

27.7 Additional Visualizations

27.7.1 Turnaround Time Distribution by Percentile

27.7.2 Heat Map: Consultations by Hour and Day of Week

27.8 Recommendations for Future Data Collection

To enhance future analyses, consider collecting:

  1. Case Characteristics:
    • Organ system
    • Diagnosis category
    • Case difficulty rating
    • Specimen type
  2. Consultation Context:
    • Reason for consultation (second opinion, expertise, educational)
    • Urgency level
    • Subspecialty area
    • Related clinical information needs
  3. Pathologist Information:
    • Years of experience
    • Subspecialty training
    • Full-time equivalent status
    • Primary responsibilities
  4. Outcome Measures:
    • Diagnostic concordance
    • Clinical utility rating
    • Follow-up consultations needed
    • Patient outcome data (if feasible)
  5. Process Metrics:
    • Time to first view (vs. completion)
    • Number of views/accesses
    • Communication events
    • Escalations or re-assignments
  6. Satisfaction Metrics:
    • Requester satisfaction
    • Consultant satisfaction
    • Perceived value

27.9 Contact Information

For questions about this analysis, data requests, or to obtain additional information, please contact the Department of Pathology administration or the corresponding author listed in the manuscript.