step 1, 2 and 3 of the implementation plan

app/Models/ScreeningAnswer.php

@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+final class ScreeningAnswer extends Model
+{
+    /**
+     * Fillable attributes for mass assignment.
+     */
+    protected $fillable = [
+        'screening_id',
+        'question_number',
+        'value',
+    ];
+
+    /**
+     * Cast attributes to specific types.
+     */
+    protected function casts(): array
+    {
+        return [
+            'screening_id' => 'integer',
+            'question_number' => 'integer',
+        ];
+    }
+
+    /**
+     * Get the screening that owns this answer.
+     */
+    public function screening(): BelongsTo
+    {
+        return $this->belongsTo(Screening::class);
+    }
+}