A validated clinical tool for suspecting laryngopharyngeal reflux (LPR). The questionnaire was proposed by Belafsky et al. (2002) and consists of 9 most common gastroesophageal reflux disease (GERD) and LPR symptoms: hoarseness or a problem with your voice; clearing your throat; excess throat mucus or postnasal drip; difficulty swallowing food, liquids, or pills; coughing after you ate or after lying down; breathing difficulties or choking episodes; troublesome or annoying cough; sensation of something sticking in your throat or a lump in your throat; heartburn, chest pain, indigestion, or stomach acid coming up. Each symptom is evaluated on a scale from 0 to 5 (0 - no complaint, 5 - severe symptom). The sum of all symptom evaluations ranges from 0 to 45.

A validated questionnaire, proposed by Ohkuma et al. (2002). Lithuanian version of the questionnaire consists of 16 questions: choking during swallowing meals / liquids; difficulty eating solid foods; difficult swallowing; feeling of food getting stuck in the throat; longer than before eating time; feeling of food remaining in the mouth; feeling that food or liquid is going up into the throat from the stomach; feeling of food being stuck in the esophagus; weight loss; food getting stuck in the throat; food falling from the mouth; difficulty coughing during or after meals; occurrence of pneumonia; hoarseness; coughing during the night. Interpretation of dysphagia screening questionnaire:

Advanced symptom - 2 points; Moderate intensity symptom - 1 point; No symptom - 0 point. At least one advanced symptom means - dysphagia. Higher score represents stronger dysphagia intensity. The maximum score is 32 points.

Self-reported height and weight were used to calculate BMI (kg/m^2). Obesity was defined as a BMI value of 30 or higher, overweight as 25.0-29.9, normal weight as 18.5-24.9, and underweight as less than 18.5

Participants were asked about their job (job title). Occupations were classified as one of 4 categories: office worker; laborer; retired; disabled

Cigarette smoking status was categorised into 4 categories: "non smoker"; "smoker"; "former smoker"; "passive smoker". Lifetime alcohol drinking status was categorized according to the frequency of alcohol use as "never"; "several times a year"; "several times a month"; "several times a week".

Participants were asked if they had their palatal tonsils removed. if yes, they were asked how long ago it happened.

The presence of gastrointestinal tract diseases was evaluated by asking participants if they were diagnosed with any disease of gastrointestinal tract. Most common were gastroesophageal reflux disease (GERD) and gastric/duodenal ulcers.

Data, found on FEGDS: erosive esophagitis (yes/no); hiatal hernia (yes/no); other gastric or duodenal pathologies.

We asked participants if they use antacid drugs, what kind of drug they use and the length of the use.

History of allergic diseases: participants checked "yes" if they were diagnosed with an allergic disease; "no" if not.

General health status was selfreported using visual analogue scale (0-excellent/ very good, 10-poor).

A validated clinical tool for suspecting laryngopharyngeal reflux (LPR). The questionnaire consists of 9 most common gastroesophageal reflux disease (GERD) and LPR symptoms: hoarseness or a problem with your voice; clearing your throat; excess throat mucus or postnasal drip; difficulty swallowing food, liquids, or pills; coughing after you ate or after lying down; breathing difficulties or choking episodes; troublesome or annoying cough; sensation of something sticking in your throat or a lump in your throat; heartburn, chest pain, indigestion, or stomach acid coming up. Each symptom is evaluated on a scale from 0 to 5 (0 - no complaint, 5 - severe symptom). The sum of all symptom evaluations ranges from 0 to 45.

Lithuanian version of the questionnaire consists of 16 questions: choking during swallowing meals / liquids; difficulty eating solid foods; difficult swallowing; feeling of food getting stuck in the throat; longer than before eating time; feeling of food remaining in the mouth; feeling that food or liquid is going up into the throat from the stomach; feeling of food being stuck in the esophagus; weight loss; food getting stuck in the throat; food falling from the mouth; difficulty coughing during or after meals; occurrence of pneumonia; hoarseness; coughing during the night. Interpretation of dysphagia screening questionnaire:

Advanced symptom - 2 points; Moderate intensity symptom - 1 point; No symptom - 0 point. At least one advanced symptom means - dysphagia. Higher score represents stronger dysphagia intensity. The maximum score is 32 points.

Participants were asked to evaluate 8 most common LTH symptoms using visual analogue scale (10 cm line, where 0 cm- no symptom, 10 cm- extremely severe symptom). Symptoms: hoarseness; difficult swallowing; painful swallowing; sensation of something sticking in your throat or a lump in your throat; difficult breathing, shortness of breath; snoring; cough; pain in the neck, pharynx.