gistfile1.txt

{
    "region": "us-west-1",
    "accountId": "111222333444",
    "eventTriggerName": "Trigger-group-us-west-3-deploy-failed",
    "applicationName": "ProductionApp-us-west-3",
    "deploymentId": "d-75I7MBT7C",
    "deploymentGroupName": "dep-group-def-456",
    "createTime": "1446744188.595",
    "completeTime": "1446744190.402",
    "deploymentOverview": {
        "Failed": "10",
        "InProgress": "0",
        "Pending": "0",
        "Skipped": "0",
        "Succeeded": "0"
    },
    "status": "Failed",
    "errorInformation": {
        "ErrorCode": "IAM_ROLE_MISSING",
        "ErrorMessage": "IAM Role is missing for deployment group: dep-group-def-456"
    }
}

Assuming this is in an object called response:

const overview = response.deploymentOverview;
const nonSucceeded = Object.keys(overview)
  .filter(key => key !== 'Succeeded')
  .reduce((sum, key) => sum + parseInt(overview[key], 10), 0);

if (nonSucceded > 0) {
  // Uh oh
}