Validation of Parkinson’s Disease-Related Questionnaires in South Africa

Table 4

Internal reliability (Cronbach’s alpha) of the modified PDQ-39.

Subscale/item	n	Alpha
Mobility		0.90
Had difficulty doing the leisure activities you would like to do?	160	0.95
Had difficulty looking after your home, e.g. repairs, housework, cooking?	159	0.95
Had difficulty carrying bags of shopping?	160	0.95
Had problems walking to the shops or church?	157	0.95
Had problems walking to your nearest neighbor?	159	0.95
Had problems getting around the house as easily as you would like?	160	0.95
Had difficulty getting around the community?	160	0.95
Needed someone else to help you when you leave the house?	160	0.95
Felt frightened or worried about falling over in public?	158	0.95
Been stuck in the house more than you would like?	160	0.95
Activities of daily living		0.82
Had difficulty washing yourself?	159	0.95
Had difficulty dressing yourself?	160	0.95
Had problems doing up your shoelaces?	160	0.95
Had problems writing clearly?	160	0.95
Had difficulty cutting up food?	158	0.95
Had difficulty holding a drink without spilling it?	160	0.95
Emotional well-being		0.90
Felt depressed?	160	0.95
Felt isolated and lonely?	158	0.95
Felt weepy or tearful?	158	0.95
Felt angry or bitter?	157	0.95
Felt anxious?	157	0.95
Felt worried about your future?	159	0.95
Stigma		0.74
Avoided eating or drinking in public?	158	0.95
Felt worried by other people’s reaction to you?	160	0.95
Social support		0.78
Had problems with your close personal relationships?	160	0.95
Lacked support in the ways you need from your spouse or partner?	157	0.95
Lacked support in the ways you need from your family or close friends?	148	0.95
Cognition		0.79
Unintentionally fallen asleep during the day?	147	0.95
Had problems concentrating, e.g. when reading or watching TV?	157	0.95
Felt your memory was bad?	158	0.95
Had distressing dreams or hallucinations?	159	0.95
Communication		0.69
Had difficulty with your speech?	160	0.95
Felt unable to communicate with people properly?	156	0.95
Felt ignored by people?	157	0.95
Bodily discomfort		0.83
Had painful muscle cramps or spasms?	159	0.95
Had aches and pains in your joints or body?	158	0.95
Felt unpleasantly hot or cold regardless of the weather?	159	0.95

PDQ-39, Parkinson’s Disease Questionnaire.