The relationship between control beliefs and self-reported adherence in adults with cystic fibrosis

Abstract

A bstract T his study investigated the relationship between locus of control and self-reported adherence in 31 adults with cystic ® brosis. Participants com pleted the M ultidimensional H ealth Locus of Control Scale, Form C (M H LC -C;W allston et al., 1994) and an adherence questionnaire. The two`powerful others' sub-scales of the M HLC-C ,`doctors' and`others' , were signi® cantly correlated with overall self-reported adherence. M ultiple regression indicated that the`doc tors' sub-scale explained 35% of the variance in overall adherence. It is concluded that an external locus of control for powerful others, especially doctors, m ay prom ote greater adherence.C ystic ® brosis (CF) is a serious genetic disorder which requires com plex daily life-long com m itm ent to m edical regim ens which are necessary to both m inimize and delay the effects of th e disease process (Harris & Super, 1995). The m ain patho physiology of CF is observed in the lungs and digestive system and treatm ent includes replacem ent of pancreatic enzym es and nutritional supplem ent, antibiotics and chest physiotherapy (Glasscoe, 1997). The advent of the C F centres, early diagnosis and improved treatm ents have led to the prediction that 50% of patients with CF will reach adulthood (Glasscoe, 1997).H ow ever, whatever th e advan ces in treatm ent, an importan t factor is how m any treatm ents patients adh ere to and what factors in¯uence such adherence. Non-adherence to m edical treatm ent is a widespread problem (see M yers & M idence, 1998), with adherence to long-te rm regim ens being estim ated at around 50% (Sackett & Snow , 1979). Research on C F has indicated that adherence is a problem in both children and adults (Abbo tt et al., 1994; for a recent review see Bryon, 1998). A search for factors which are associated with poor adherence in CF has been inconclusive. H ow ever, in a recent study of adults with CF, Abbo tt et al. (1996) m easured health locus of control (HLC ) with the generic M ultidimensional H ealth Locus of C ontrol Scale (M H LC ; W allston et al., 1978), the m ost com m only used m easure of H LC. The M HLC recognizes different control beliefs which are m easured by three separate scales: an internal scale, and

Adherence of Subjects With Cystic Fibrosis to Their Home Program: A Systematic Review

“…All other papers (n ϭ 10) simply summarized treatment as airway clearance techniques or chest physical therapy. Adherence rates ranged from 33.3 Ϯ 43.15% 23 to 91.2% 28 by patient questionnaire.…”

“…Some studies used multiple methods of assessment. Two studies used electronic monitoring via an adaptive aerosol delivery device, 33,34 3 used participant questionnaires, 3,25,31 2 used parent questionnaires, 3,23 one used daily telephone diaries, 3 one used pharmacy refill data, 35 and one used data from a research database of health-care claims 20 to assess adherence. Mean overall percentage of adherence ranged from 36.1 Ϯ 35.6% by daily telephone diary 3 to 85.0 Ϯ 33.7% by patient questionnaire.…”

“…All but one study was of low quality. Four studies used participant questionnaires, 3,23,25,29 2 used parent questionnaires, 3,22 one used clinician questionnaires, 22 3 used interviews via telephone, 3,41,42 and one used pharmacy refill data and electronic recordings via MEMS SmartCap. 3 Mean adherence ranged from 22.2 Ϯ 34.2% by daily telephone diary 3 to 97.5 Ϯ 7.5% by parent questionnaire.…”

“…3,10,11,20,[22][23][24][25][27][28][29][31][32][33][34][35][36][37][38][39] Eighteen papers were of low quality, and 2 were of moderate quality. The categories of medications are summarized below (Table 3).…”

“…All but one study was of low quality. Eight studies used participant questionnaires, 3,4,23,[25][26][27]30,31 4 used parent questionnaires, 3,22,28,30 , 2 used clinician questionnaires, 22,27 one used caregiver questionnaires, 24 and one used daily telephone diaries. 3 Only 2 papers of low quality 30,31 specified the individual aspects of chest physical therapy involved (positive expiratory pressure, coughing, active cycle of breathing technique, chest wall percussion, chest wall vibrations).…”