diff --git a/src/main/java/uk/ac/cam/cl/dtg/isaac/api/Constants.java b/src/main/java/uk/ac/cam/cl/dtg/isaac/api/Constants.java
index 24ee0b91c..9bbd2ddae 100644
--- a/src/main/java/uk/ac/cam/cl/dtg/isaac/api/Constants.java
+++ b/src/main/java/uk/ac/cam/cl/dtg/isaac/api/Constants.java
@@ -73,7 +73,13 @@ public enum GameboardItemState {
     }
 
     public enum CompletionState {
-        ALL_CORRECT, IN_PROGRESS, NOT_ATTEMPTED
+        ALL_CORRECT, IN_PROGRESS, NOT_ATTEMPTED;
+
+        private static final Set<CompletionState> allStates = Set.of(CompletionState.values());
+
+        public static Set<CompletionState> getAllStates() {
+            return allStates;
+        }
     }
 
     public enum QuestionPartState {
diff --git a/src/main/java/uk/ac/cam/cl/dtg/isaac/api/PagesFacade.java b/src/main/java/uk/ac/cam/cl/dtg/isaac/api/PagesFacade.java
index c3e60d045..24478b34f 100644
--- a/src/main/java/uk/ac/cam/cl/dtg/isaac/api/PagesFacade.java
+++ b/src/main/java/uk/ac/cam/cl/dtg/isaac/api/PagesFacade.java
@@ -388,28 +388,31 @@ public final Response getQuestionList(@Context final Request request,
         }
 
         try {
-            if (null == statuses || Objects.equals(statuses, "")) {
-                // If no statuses apply assume all statuses
-                filterByStatuses = Set.of(CompletionState.values());
+            if (null == statuses) {
+                // If statuses isn't a URL param, we won't augment or filter!
+                filterByStatuses = null;
+            } else if (statuses.isEmpty()) {
+                // If statuses is blank, that shouldn't mean "please match nothing at all"; make it match everything.
+                filterByStatuses = CompletionState.getAllStates();
             } else {
                 filterByStatuses = Arrays.stream(statuses.split(","))
                         .map(CompletionState::valueOf)
                         .collect(Collectors.toSet());
             }
         } catch (IllegalArgumentException e) {
-            return new SegueErrorResponse(
-                    Status.BAD_REQUEST, "Invalid question statuses to filter by provided.", e
-            ).toResponse();
+            return new SegueErrorResponse(Status.BAD_REQUEST, "Invalid question status filter provided.").toResponse();
         }
 
         String validatedSearchString = searchString.isBlank() ? null : searchString;
 
-        // Show content tagged as "nofilter" if the user is staff
-        boolean showNoFilterContent;
+        // Show content tagged as "nofilter" if the user is staff:
+        boolean showNoFilterContent = false;
         try {
-            showNoFilterContent = isUserStaff(userManager, httpServletRequest);
+            if (user instanceof RegisteredUserDTO) {
+                showNoFilterContent = isUserStaff(userManager, (RegisteredUserDTO) user);
+            }
         } catch (NoUserLoggedInException e) {
-            showNoFilterContent = false;
+            // This cannot happen!
         }
 
         List<ContentSummaryDTO> combinedResults = new ArrayList<>();
@@ -440,13 +443,15 @@ public final Response getQuestionList(@Context final Request request,
 
                 List<ContentSummaryDTO> unfilteredSummarizedResults = new ArrayList<>(summarizedResults);
 
-                if (user instanceof RegisteredUserDTO) {
-                    summarizedResults = userAttemptManager.augmentContentSummaryListWithAttemptInformation(
-                            (RegisteredUserDTO) user, summarizedResults
-                    );
-                    summarizedResults = summarizedResults.stream()
-                            .filter(q -> filterByStatuses.contains(q.getState()))
-                            .collect(Collectors.toList());
+                if (null != filterByStatuses) {
+                    // Only augment when filtering by statuses:
+                    summarizedResults = userAttemptManager.augmentContentSummaryListWithAttemptInformation(user, summarizedResults);
+                    // Optimise out unnecessary filtering:
+                    if (!filterByStatuses.equals(CompletionState.getAllStates())) {
+                        summarizedResults = summarizedResults.stream()
+                                .filter(q -> filterByStatuses.contains(q.getState()))
+                                .collect(Collectors.toList());
+                    }
                 }
 
                 if (limit < 0 || combinedResults.size() + summarizedResults.size() <= limit) {
diff --git a/src/main/java/uk/ac/cam/cl/dtg/isaac/api/managers/UserAttemptManager.java b/src/main/java/uk/ac/cam/cl/dtg/isaac/api/managers/UserAttemptManager.java
index 9e683c53e..a45a0afbc 100644
--- a/src/main/java/uk/ac/cam/cl/dtg/isaac/api/managers/UserAttemptManager.java
+++ b/src/main/java/uk/ac/cam/cl/dtg/isaac/api/managers/UserAttemptManager.java
@@ -6,6 +6,7 @@
 import uk.ac.cam.cl.dtg.isaac.dto.content.ContentBaseDTO;
 import uk.ac.cam.cl.dtg.isaac.dto.content.ContentDTO;
 import uk.ac.cam.cl.dtg.isaac.dto.content.ContentSummaryDTO;
+import uk.ac.cam.cl.dtg.isaac.dto.users.AbstractSegueUserDTO;
 import uk.ac.cam.cl.dtg.isaac.dto.users.RegisteredUserDTO;
 import uk.ac.cam.cl.dtg.segue.api.managers.QuestionManager;
 import uk.ac.cam.cl.dtg.segue.dao.SegueDatabaseException;
@@ -99,12 +100,20 @@ private void augmentContentSummaryWithAttemptInformation(
      * @return the augmented content summary list.
      * @throws SegueDatabaseException if there is an error retrieving question attempts.
      */
-    public List<ContentSummaryDTO> augmentContentSummaryListWithAttemptInformation(RegisteredUserDTO user, List<ContentSummaryDTO> summarizedResults) throws SegueDatabaseException {
-        List<String> questionPageIds = summarizedResults.stream().map(ContentSummaryDTO::getId).collect(Collectors.toList());
+    public List<ContentSummaryDTO> augmentContentSummaryListWithAttemptInformation(AbstractSegueUserDTO user, List<ContentSummaryDTO> summarizedResults) throws SegueDatabaseException {
 
-        Map<String, Map<String, List<LightweightQuestionValidationResponse>>> questionAttempts =
-                questionManager.getMatchingLightweightQuestionAttempts(Collections.singletonList(user), questionPageIds)
-                        .getOrDefault(user.getId(), Collections.emptyMap());
+        Map<String, ? extends Map<String, ? extends List<? extends LightweightQuestionValidationResponse>>> questionAttempts;
+
+        if (user instanceof RegisteredUserDTO) {
+            // Load only relevant attempts:
+            RegisteredUserDTO registeredUser = (RegisteredUserDTO) user;
+            List<String> questionPageIds = summarizedResults.stream().map(ContentSummaryDTO::getId).collect(Collectors.toList());
+            questionAttempts = questionManager.getMatchingLightweightQuestionAttempts(Collections.singletonList(registeredUser), questionPageIds)
+                    .getOrDefault(registeredUser.getId(), Collections.emptyMap());
+        } else {
+            // For anon users, all attempts are in one place so just load all:
+            questionAttempts = questionManager.getQuestionAttemptsByUser(user);
+        }
 
         for (ContentSummaryDTO result : summarizedResults) {
             augmentContentSummaryWithAttemptInformation(result, questionAttempts);