diff --git a/app/controllers/overview_controller.rb b/app/controllers/overview_controller.rb
index 9ed920dc..bbd84bc3 100644
--- a/app/controllers/overview_controller.rb
+++ b/app/controllers/overview_controller.rb
@@ -29,10 +29,10 @@ class OverviewController < SqmApplicationController
   end
 
   def measures
-    @measures ||= Measure.all.includes(%i[scales admin_data_items category])
+    @measures ||= Measure.all.includes(%i[scales admin_data_items category subcategory])
   end
 
   def subcategories
-    @subcategories ||= Subcategory.all
+    @subcategories ||= Subcategory.all.includes(:measures)
   end
 end
diff --git a/app/models/measure.rb b/app/models/measure.rb
index 22c0ad4e..d13aa2f3 100644
--- a/app/models/measure.rb
+++ b/app/models/measure.rb
@@ -25,14 +25,15 @@ class Measure < ActiveRecord::Base
   end
 
   def student_survey_items_with_sufficient_responses(school:, academic_year:)
-    SurveyItem.where(id: SurveyItem.joins('inner join survey_item_responses on survey_item_responses.survey_item_id = survey_items.id')
-                                .student_survey_items
-                                .where("survey_item_responses.school": school,
-                                       "survey_item_responses.academic_year": academic_year,
-                                       "survey_item_responses.survey_item_id": survey_items.student_survey_items)
-                                .group('survey_items.id')
-                                .having('count(*) >= 10')
-                                .count.keys)
+    @student_survey_items_with_sufficient_responses ||=
+      SurveyItem.where(id: SurveyItem.joins('inner join survey_item_responses on survey_item_responses.survey_item_id = survey_items.id')
+                                      .student_survey_items
+                                      .where("survey_item_responses.school": school,
+                                             "survey_item_responses.academic_year": academic_year,
+                                             "survey_item_responses.survey_item_id": survey_items.student_survey_items)
+                                      .group('survey_items.id')
+                                      .having('count(*) >= 10')
+                                      .count.keys)
   end
 
   def teacher_scales
diff --git a/db/migrate/20230610165508_add_survey_item_index_to_survey_item_responses.rb b/db/migrate/20230610165508_add_survey_item_index_to_survey_item_responses.rb
new file mode 100644
index 00000000..45a11c3f
--- /dev/null
+++ b/db/migrate/20230610165508_add_survey_item_index_to_survey_item_responses.rb
@@ -0,0 +1,6 @@
+class AddSurveyItemIndexToSurveyItemResponses < ActiveRecord::Migration[7.0]
+  def change
+    add_index :survey_item_responses, %i[school_id academic_year_id survey_item_id],
+              name: 'by_school_year_and_survey_item'
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index b19147f0..99a36ddd 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.0].define(version: 2023_05_17_191736) do
+ActiveRecord::Schema[7.0].define(version: 2023_06_10_165508) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -448,6 +448,7 @@ ActiveRecord::Schema[7.0].define(version: 2023_05_17_191736) do
     t.index ["academic_year_id"], name: "index_survey_item_responses_on_academic_year_id"
     t.index ["gender_id"], name: "index_survey_item_responses_on_gender_id"
     t.index ["response_id"], name: "index_survey_item_responses_on_response_id"
+    t.index ["school_id", "academic_year_id", "survey_item_id"], name: "by_school_year_and_survey_item"
     t.index ["school_id", "academic_year_id"], name: "index_survey_item_responses_on_school_id_and_academic_year_id"
     t.index ["school_id", "survey_item_id", "academic_year_id", "grade"], name: "index_survey_responses_on_grade"
     t.index ["school_id"], name: "index_survey_item_responses_on_school_id"