AutoSendReminder

Overview

AutoSendReminderTask resends previously sent patient letters that have not been viewed after configured resend intervals. It evaluates all auto-sent letters against AutoSendLetterConfig reminder criteria, identifies letters needing follow-up, and resends them via email or SMS while tracking reminder attempt counts.

Use this task when: You need to automatically follow up with patients who haven't viewed their cost estimate letters, ensuring critical payment information reaches patients through repeated delivery attempts.

Don't use this task when:

• Initial letter sending (use AutoSendLettersTask or AutoSendLettersForFutureVisitsTask instead)
• Manually resending a single letter (use the UI letter management features)
• Testing letter delivery (reminder logic requires existing send events and proper time intervals)

Parameters

Execution Flow

flowchart TD
    A[Start AutoSendReminder] --> B[Load all AutoSendLetterConfigs with reminders enabled]
    B --> C{Any configs with AttemptResend=true?}
    C -->|No| Z[End - No reminders configured]
    C -->|Yes| D[For each AutoSendLetterConfig]

    D --> E[Calculate intervalOffset = Today - ResendInterval days]
    E --> F[Query PatientLetters needing resend]
    F --> G{Query filters}

    G --> H[AutoSent = true]
    H --> I[ViewedDate IS NULL]
    I --> J[AutoResendAttempts < MaxResendAttempts]
    J --> K[Last send event >= intervalOffset]
    K --> L[Most recent letter per visit/invoice]

    L --> M{Any letters found?}
    M -->|No| D
    M -->|Yes| N[Load related Visits, Patients, Facilities]

    N --> O[For each PatientLetter]
    O --> P[Create PatientLetterSendEvent with current date]
    P --> Q[Send letter via email/SMS using LetterHandler]
    Q --> R[Log API response]
    R --> S[Increment letter.AutoResendAttempts]

    S --> T{More letters for this config?}
    T -->|Yes| O
    T -->|No| U[Save all PatientLetterSendEvents in bulk]
    U --> V[Save all updated PatientLetters in bulk]

    V --> W{More configs?}
    W -->|Yes| D
    W -->|No| Z[End]

    style F fill:#e1f5ff
    style Q fill:#fff4e1
    style U fill:#e1f5ff
    style V fill:#e1f5ff

Processing Algorithm

The task uses date-based interval logic to determine which letters need reminders:

Reminder Selection Algorithm

1. Load Eligible Configs: Select all AutoSendLetterConfig records where:

   • AttemptResend = true
   • ResendInterval is not null
   • MaxResendAttempts != 0

2. For Each Config: Calculate which letters need reminders using:

   intervalOffset = CurrentDate - config.ResendInterval (in days)
   

3. Filter PatientLetters by the following cumulative criteria:

   • AutoGenerated = true (generated by auto-send system)
   • AutoSent = true (successfully sent initially)
   • ViewedDate IS NULL (patient hasn't viewed the letter)
   • AutoResendAttempts < config.MaxResendAttempts (haven't exhausted attempts)
   • Associated with the AutoSendLetterConfig via PatientLetterSendEvent
   • Most recent PatientLetterSendEvent.CreatedOn date >= intervalOffset
   • Most recent letter per Visit/Invoice combination (no duplicates)

4. Send Reminders: For each qualifying letter:

   • Create new PatientLetterSendEvent with current timestamp
   • Resend letter using existing LetterHandler (same logic as initial send)
   • Increment AutoResendAttempts counter on the letter
   • Log email/SMS API response

5. Bulk Save: Save all send events and updated letters in two bulk operations

Example Execution

Scenario: AutoSendLetterConfig with ResendInterval=3 days, MaxResendAttempts=2

Config: AutoSendLetterConfig-01
  ResendInterval: 3 days
  MaxResendAttempts: 2
  AttemptResend: true

PatientLetter: PL-1 (for Visit V-1)
  AutoSent: true
  ViewedDate: null (not viewed)
  AutoResendAttempts: 0

  Send Events:
    - Event 1: Created 2024-01-01 (initial send)

Current Date: 2024-01-04 (3 days later)
intervalOffset: 2024-01-04 - 3 = 2024-01-01

Evaluation:
  ✓ AutoSent = true
  ✓ ViewedDate IS NULL
  ✓ AutoResendAttempts (0) < MaxResendAttempts (2)
  ✓ Last event (2024-01-01) >= intervalOffset (2024-01-01)

Result: SEND REMINDER
  - Create Event 2 with CreatedOn = 2024-01-04
  - Resend letter via email/SMS
  - Increment AutoResendAttempts to 1

Next Reminder: 2024-01-07 (3 days later, attempt 2/2)
Final Attempt: After 2024-01-07, no more reminders (MaxResendAttempts reached)

Letter Viewed During Reminder Period

PatientLetter: PL-2
  AutoResendAttempts: 1
  ViewedDate: 2024-01-03 (patient viewed letter)

Evaluation:
  ✓ AutoSent = true
  ✗ ViewedDate IS NOT NULL

Result: NO REMINDER (patient already viewed)

Usage Examples

Example 1: Scheduled daily execution

// Run daily at 9:00 AM to send reminders for unviewed letters
var task = new AutoSendReminderTask();
// No parameters - all configuration is in AutoSendLetterConfig entities
// The task automatically processes all configs with AttemptResend=true

Example 2: Part of patient engagement pipeline

// Step 1: Initial letter send for upcoming visits
var initialSendTask = new AutoSendLettersForFutureVisitsTask();

// Step 2 (3 days later): Follow up with patients who haven't viewed
var reminderTask = new AutoSendReminderTask();
// Automatically identifies and resends letters based on ResendInterval

Example 3: Configuration-driven reminder strategy

// AutoSendLetterConfig configured in UI with:
// - ResendInterval: 2 days
// - MaxResendAttempts: 3
// - AttemptResend: true
//
// Timeline:
// Day 0: Initial letter sent (AutoSendLettersTask)
// Day 2: First reminder (AutoSendReminderTask, attempt 1/3)
// Day 4: Second reminder (AutoSendReminderTask, attempt 2/3)
// Day 6: Final reminder (AutoSendReminderTask, attempt 3/3)
// Day 8+: No more reminders (MaxResendAttempts reached)

var task = new AutoSendReminderTask();

Related Tasks Comparison

Key Differentiators:

• AutoSendReminder only resends existing letters; it never creates new letters
• AutoSendReminder requires prior execution of AutoSendLettersTask or AutoSendLettersForFutureVisitsTask
• AutoSendLetters* tasks create PatientLetter and initial PatientLetterSendEvent records
• AutoSendReminder creates additional PatientLetterSendEvent records and increments AutoResendAttempts
• All three tasks use the same LetterHandler for actual email/SMS delivery

Typical Pipeline:

AutoSendLettersTask → (wait ResendInterval days) → AutoSendReminderTask → (repeat until MaxResendAttempts)

Performance Considerations

Database Impact

• Tables Read:
  • AutoSendLetterConfig: Single query for all configs with reminders enabled
  • PatientLetter: Filtered query per config using resend criteria (indexed by AutoSent, ViewedDate)
  • PatientLetterSendEvent: Used to determine last send date and identify letters needing reminders
  • Visit: Loaded for all letters needing reminders
  • Patient: Loaded for all letters needing reminders
  • Facility: Loaded for visits needing reminders
• Tables Written:
  • PatientLetterSendEvent: Bulk insert of new send events (one per reminder)
  • PatientLetter: Bulk update of AutoResendAttempts counter
  • MessageAPILog: Per-reminder logging of email/SMS API responses
• Query Patterns:
  • Single query to load reminder-enabled configs
  • Per-config query for letters needing resend (optimized with indexes)
  • Batch loading of related entities (visits, patients, facilities)
  • Dictionary lookups for entity relationships (no N+1 queries)
• External API Calls:
  • One email or SMS API call per letter reminder
  • API rate limits may affect throughput for high-volume reminders

Optimization Tips