Supplementary Table 1: Items from the most promising pain assessment instruments categorized in Domains 1 – 3 of the AGS criteria

AGS domain 1 AGS domain 2 AGS domain 3 Facial expression Vocalization Body movements Tool ABBEY Looking tense, Whipering, groaning, crying Fidgeting, rocking, guarding part of (Abbey 2004) frowning, grimacing, body, withdrawal looking frightened ADD Grimacing, Moaning, mumbling, chanting, Tense, wringing hands, clenched fists, (Kovach 2001) frowning, blinking, grunting, whining, calling out restless, rubbing/holding body part tightly closed or Screaming, crying, verbally hyper- or hypoactive, wandering, widely open eyes, aggressive guarding body part, noisy breathing, frightened, weepy, resistance to care worried, sad CNPI Furrowed brow, Sighs, gasps, moans, groans, cries, Bracing (clutching or holding onto (Feldt 2000) narrowed eyes, words ("ouch," "that hurts") cursing furniture, equipment, or affected area clenched teeth, during movement; ["stop," "that's during movement), rubbing, massaging tightened lips, jaw enough") affected area, restless, rocking drop, distorted expressions DS-DAT Sad: trouble looking Noise or speech with negative or Tens: extremities show tension, wringing (Hurley et al., 1992) face, looking hurt, disapproving quality, hushed low hands, clenched fist, or knees pulled up worried, lost or sounds such as constant muttering tightly, being in a strained and inflexible lonesome, distressed with a guttural tone, monotone, position appearance, sunken, subdued, or varying pitched noise Fidgeting: restless impatient motion, acts “hang dog”, with a definite unpleasant sound, squirming or jittery, appearance of trying lackluster eyes, tears, moaning, groaning, repeating the to get away from hurt area, forceful crying; Frightened: same words, expressing hurt or pain touching, tugging, or rubbing body parts scared, concerned, bothered fearful or troubled, alarmed experience with open eyes and pleading face; Frown: looks strained, stern or scowling looks, displeased, wrinkled brow, creases in forehead, corners of mouth turned down

DOLOPLUS 2 Grimaces, Drawn, Words, moans, cries, voiceless, Gesture, protective actions against any (Lefebvre-Chapiro 2001) atonic fixed gaze complaints investigation or nursing, protective empty gaze, absent, actions taken at rest, even when not tears approached, restlessness EPCA-2 Anxious look on the Complains when caregiver is present, Watchful expression, seems to fear both (Morello 2007) face, grimaces from moans or cries silently, spontaneously, movement and caregiver intervention, time to time, shouts or complains violently and/or holds back or guides the hands of the frightened look, spontaneously caregiver, adopts a comfortable position, tense facial shows resistance when being moved or expression, totally during caregiver intervention, rigid expression restlessness MOBID-2 Grimacing, Ouch! Groaning, gasping, screaming Freezing, guarding, pushing, crouching (Husebo 2010) frowning, tightening mouth, closing eyes NOPPAIN Grimaces, furrowed “ That hurts!”, “Ouch!”, cursing, Rigidity, holding, guarding (especially (Snow 2004) brow, winces, “Stop that!” moans, groans, grunts, during movement), massaging affected feared , worried cries, gasps, sighs areas, restlessness, rocking

PACSLAC Grimacing, sad look, Verbal aggression Screaming/Yelling, Fidgeting, pulling away, flinching, (Fuchs-Lacelle 2004) tighter face, dirty grunting, calling out (i.e. for help) restless, pacing, wandering, trying to look, change in eyes crying, specific sound or vocalization leave, refusing to move, thrashing, (squinting, dull, for pain ‘ow’, ouch’, moaning and decreased activity, refusing medications, bright, increased groaning, mumbling moving slow, repetitive movements, movement), uncooperative, resistant to care, guarding frowning, pain sore area, touching/holding sore area, expression, grim limping, clenched fist, going into fetal face, clenching teeth, position, stiff, rigid wincing, opening mouth, creasing forehead, screwing up nose, teary eyed, pale face PAINAD Sad (unhappy, Occasional moan or groan (mournful Tense (strained, apprehensive or worried, (Warden 2003) lonesome, sorrowful, and murmuring sounds, wails or jaw may be clenched) dejected look, tears laments, inarticulate involuntary Distressed pacing (unsettled activities, in the eyes); sounds); low level speech with a fearful, worried or disturbed) frightened (look of negative or disapproving quality Fidgeting (restless movement, squirming fear, alarm, (muttering, mumbling, whining, or wiggling, hitching a chair across the heightened anxiety, grumbling, swearing, complaining, room, repetitive touching, tugging, eyes wide open); sarcastic or caustic tone), repeated rubbing body parts) frown(downward troubled calling out (phrases/words Rigid (stiffening of the body, arms and corners of the mouth, used over and over in a tone that legs are tight and inflexible, straight and wrinkling in the suggests anxiety, uneasiness, unyielding trunk); fists clenched (tightly forehead and around distress); loud moaning or groaning closed hands, opened and closed the mouth), (mournful or murmuring sounds, repeatedly); knees pulled up (flexing grimacing (distorted, wails or laments louder than usual, legs, drawing knees toward chest, distressed look, brow often abruptly beginning and ending); troubled appearance); pulling or pushing is more wrinkled as crying (utterance of emotion away (resistiveness to care, trying to is the area around the accompanied by tears, sobbing and escape by yanking or wrenching, shoving mouth, eyes may be quiet weeping) away) squeezed shut) Striking out (hitting, kicking, grabbing, punching, biting) PADE Sad, anxious, Groaning, moaning, vocalization, Tense body language, restlessness, guard (Villanueva 2003) frightened, frowning, sounds distress, gasping effective areas, breathing loud, breathing grimace, brace rapidly, hyperventilation

PAINE Showing tension in Moaning, grunting, groaning, Rigidity/resistance to movements: (Cohen-Mansfield 2006) the face, frowning, gasping, sighing, crying, whimpering, Cringing, body stiffens when touched tightening the eyes, whining, screaming, yelling Avoiding touch or use of affected area, squinting, clenching pulling you toward self (toward the or grinding teeth resident); Guarding: Abnormally stiff, interrupted, rigid movement, limping, dragging foot, impaired walking; Bracing: Leaning on wall, chair to maintain stability; moodiness, irritation, or depressed mood, seems sad, angry; Posturing: Strange, awkward standing or sitting positions, weird movements, restlessness