Appropriate utilization of treatment with systemic therapy remains problematic in advanced lung cancer. A major issue continues to be over-treatment. Contributors to this include barriers in communication concerning patients' wishes and goals, lack of formal monitoring of symptoms using validated health-related quality of life (QL) and patient reported outcomes (PROs) assessment, and over-dependence on imaging studies as the major and often sole assessment tool. All of these factors make quality decision making more difficult and can lead to decisional conflict and patient and family regret with treatment. The primary specific aim is to test the hypothesis that use of a decision aid to enhance informed, shared decision making coupled with QL assessment with immediate results in patients with advanced lung cancer receiving first, second, or third-line therapy will lead to a reduction in two major contributors of cost (number of chemotherapy cycles administered and the number of advanced imaging studies \[CT, MRI, PET\] related to treatment decisions) compared with the control arm. Secondary aims are: 1) To test the hypothesis that patients with advanced lung cancer who receive an intervention decision aid coupled with immediate QL-PRO results) will have reduced decisional conflict, and reduced decisional regret related to the decision-making process, than those who do not; and 2) to explore the hypothesis that patients with advanced lung cancer who have greater agreement with their chosen supporter (less difference in perception of QL-PROs between the patient and the supporter) will have fewer chemotherapy cycles, than those who do not have close agreement. This phase III, two-arm, prospective, randomized clinical trial (RCT) will test the use of a decision aid ("DecisionKEYS") for patients with advanced lung cancer and coupled with the validated, Electronic Lung Cancer Symptom Scale ("eLCSS-QL") to provide immediate QL-PRO results over the treatment period. A repeated measures design will obtain QL assessment at baseline, every 3 weeks while chemotherapy is given, and at the completion of chemotherapy. This study will use a pretest/ posttest design covering timing for each of three consequential decisions of cancer chemotherapy: Decision 1 ("Starting Chemotherapy"), Decision 2 ("Changing Chemotherapy"), and Decision 3 ("Stopping Anti-Cancer Treatment"). There will be three entry points: patients can be entered into the trial either at their initial chemotherapy, or at the time of starting 1st-, 2nd- or 3rd-line chemotherapy. A stratified block randomization design will be used in which strata are determined by two variables: line of therapy and presenting quality of life. This RCT will be conducted in the outpatient setting at three cancer centers in three states. The sample will include 196 patients with advanced non-small cell lung cancer and their chosen supporter (if available). The sampling plan will include serially screening the clinic appointment roster in the clinics. QL-PRO assessment, decisional conflict, and decisional regret will be used to evaluate response to the decision aid. A specific protocol will be followed by the physician and study nurse at each visit. Descriptive statistics, subgroup analyses (t-test), and Generalized Linear Model (GLM) method will be used for analyses.