Table 1.
Characteristics of included studies
| First author (year) | Country | Study design | HD sample, N | Age (mean) | Gender (male, %) | Other groups, N | Statistical comparison with(in) group(s) | Study aim | Intended concept | Method of (HR)QoL assessment | Appraisal score (MMAT, QoL) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| (HR)QoL evaluation studies | |||||||||||
| Chapman (2002) [33] | UKa | Qualitative—phenomenological approach | NSb, 21 | 42 | 43% |
CF, 31 Unaffected carriers/family, 11 |
No | To present perceptions of health and QoL in individuals with early- or late-onset genetic conditions | QoL + | Individual interviews | 60%, 0% |
| Ready (2011) [32] | USA | Qualitative—consensual qualitative research approach | pHDGECs, 9 | 38 | 44% | Companions, 6 | No | To explore perceptions of QoL in pHDGECs and companions | QoL + | Individual interviews | 80%, 0% |
| Calvert (2013) [29] | UK | Quantitative non-randomized—analytical cross-sectional design | mHDGECsb, 53 | 57 | 45% | rLTND, 213 | Yes | To assess HRQoL and access to supportive health and social care in individuals with rare long-term neurological conditions | HRQOL + | EQ-5Dc | 40%, 13% |
| Carlozzi (2013) [36] | USA | Qualitative—theoretical framework/participatory action approach | mHDGECsd, 24 | 49 | NR |
At-risk/prodromal, 16 Caregivers, 17 HD clinicians, 25 |
No | To explore domains that reflect HRQOL in HD and to identify pre-existing measures of HRQoL relevant to HD | HRQoL + | Focus groups | 100%, 100% |
| Chisholm (2013) [40] | USA | Quantitative non-randomized—analytical cross-sectional design |
pHDGECs, 37 mHDGECs, 31 |
44 47 |
27% 56% |
At-risk, 65 Healthy controls, 95 |
Yes | To evaluate and compare well-being (including QoL) in persons at-risk for HD, pHDGECs, mHDGECs, and controls | QoL + | Single item (item not defined) | 40%, 13% |
| Read (2013) [26]e | Multinational (not defined) | Quantitative non-randomized—analytical cross-sectional design |
pHDGECs, 118 group A, Bf mHDGECs, 117 group C, Dg |
41, 40 47, 51 |
46%, 44% 39%, 55% |
Partners, 84 Siblings, 36 |
Yes | To explore HRQoL in pHDGECs and mHDGECs compared to a control group of individuals from the HD community | HRQoL + − | SF-36c, QoLIc | 80%, 25% |
| Dorey (2016) [35] | Spain | Quantitative descriptive—descriptive cross-sectional design | mHDGECs, 55 | 50 | 49% | Caregivers, 55 | No | To explore and compare HRQoL in mHDGECs using a disease-specific and generic questionnaire | HRQoL + |
EQ-5Dc H-QoL-Ih |
40%, 13% |
| Varda (2016) [23]e | Cyprus | Quantitative non-randomized—analytical cross-sectional design |
pHDGECs, 9 mHDGECs, 23 |
53i | 38%j | Yes | To evaluate QoL in individuals with HD using a standardized HRQoL questionnaire | QoL − | EQ-5Dc | 100%, 38% | |
| Sherman (2019) [37] | USA | Qualitative—theoretical framework/participatory action approach |
mHDGECsd, 24 Early (n = 8) Advanced (n = 16) |
50 50 |
37% 56% |
At-risk/prodromal, 16 Caregivers, 17 HD clinicians, 25 |
No | To explore experiences of chorea and its impact on everyday functioning and HRQoL in HD stakeholders | HRQoL + | Focus groups | 60%, 0% |
| Exuzides (2022) [42] | USA | Quantitative non-randomized—analytical cross-sectional design | mHDGECs, 41 | 46 | 32% |
HD carers, 80 PD, 118 PD carers, 385 Controls, 123 Control carers, 240 |
Yes | To evaluate the unique and shared burdens, including the impact on HRQoL, of mHDGECs and HD care partners, compared to Parkinson’s Disease and the general population | HRQoL + | EQ-5Dc | 100%, 25% |
| Engels (2022) [38] | NL | Qualitative—descriptive and explorative approach | mHDGECs, 36 | NRk | 39% |
Family members, 11 Nurses, 36 |
No | To explore and describe perceived QoL of HD patients from the perspective of mHDGECs, family members, and nursing staff | QoL + | Individual interviewsl | 100%, 50% |
| Studies examining associations of (HR)QoL | |||||||||||
| Ready (2008) [39]e | USA | Quantitative non-randomized—longitudinal design | mHDGECs, 22 | 47 | 73% | Caregivers, 22 | No | To examine relationships between patient QoL, caregiver QoL, and symptoms of HD | QoL + | Single item (Overall, how would you rate your QoL?) | 40%, 50% |
| Ho (2009) [45] | UK | Quantitative non-randomized—analytical cross-sectional design | mHDGECsb, 70 | 50 | 50% | To examine which variables are linked with HRQOL in mHDGECs | HRQoL + | SF-36c | 60%, 25% | ||
| McCabe (2009a) [34] | Australiaa | Quantitative non-randomized—longitudinal design | NSb, 26 | 59 | 69% |
PD, 100 MND, 52 MS, 79 |
Yes | To identify predictors of economic pressure and QoL in individuals with progressive neurological illness | QoL + | WHOQoL-BREFc | 40%, 25% |
| Banaszkie- wicz (2012) [24] | Poland | Quantitative non-randomized—analytical cross-sectional design | mHDGECsb, 80 | 48 | NR | Caregivers, 80 | No | To determine predictors of patients’ disability, QoL and caregivers' burden in HD | QoL − | SF-36c | 60%, 13% |
| Eddy (2013) [19] | UK | Quantitative non-randomized—analytical cross-sectional design | mHDGECsb, 20 | 54 | 60% | To examine associations between QoL, behavioral and psychiatric symptoms, and executive function in mHDGECs | QoL − | SF-36c | 20%, 25% | ||
| Eddy (2014) [20] | UKa | Quantitative non-randomized—analytical cross-sectional design | mHDGECs, 30 | 55 | 60% | Healthy controls, 20 | No | To assess associations between spatial/social perspective taking and executive deficits, everyday perspective taking, motor symptoms, functional capacity and QoL in mHDGECs | QoL − | SF-36c | 40%, 13% |
| Brugger (2015) [43] | Austria | Quantitative non-randomized—analytical cross-sectional design | mHDGECsb, 80 | NR | 54% | To assess the impact of disease characteristics on HRQoL in HD | HRQoL + | SF-36c | 60%, 25% | ||
| van Walsem (2016) [30] | Norway | Quantitative non-randomized—analytical cross-sectional design | mHDGECs, 84 | 57 | 56% | To assess ATC use across disease stages in mHDGECs and to examine the associations between ATC and HRQoL | HRQoL + | EQ-5Dc | 80%, 13% | ||
| Fritz (2018) [44] | USA | Quantitative non-randomized—analytical cross-sectional design |
pHDGECs, 193 mHDGECs, 278 |
49 j | 40% j | To examine associations between apathy, functional status, physical function, cognitive function, behavioral status/emotional function and HRQoL in HD | HRQoL + |
EQ-5Dc RAND-12c WHODASc |
60%, 13% | ||
| Zielonka (2018) [22]e | Mixed (EU) | Quantitative non-randomized—analytical cross-sectional design | mHDGECs, 1166 | NR for subsample | 52% | To compare if gender differences in motor, cognitive and behavioral symptoms affect function and how functional impairment affects QoL in mHDGECs | QoL − | SF-36c | 100%, 13% | ||
| Ready (2019) [25] | USAa | Quantitative non-randomized—longitudinal design |
pHDGECs, 50 mHDGECs, 272 |
52 j | 46% j | To assess the relationship between positive affect and HRQOL outcomes in HD and whether these associations were moderated by functional status | HRQoL + − |
PROMISc Neuro-QoLc HDQLIFEh |
80%, 13% | ||
| Studies investigating both (HR)QoL and its associated factors | |||||||||||
| Licklederer (2008) [21] | Germany | Quantitative non-randomized—analytical cross-sectional design |
pHDGECs, 54 mHDGECs, 15 |
NR for subsamples | NR for subsamples | Non-carriers, 52 | Yes | To examine mental health and QoL in HD, to compare mental health between non-carriers, pHDGECs and mHDGECs, and to determine predictors of mental health and QoL | QoL– | SF-12c | 80%, 25% |
| McCabe (2009b) [41] | Australia | Quantitative non-randomized—analytical cross-sectional design | mHDGECsb, 48 | 57 | 63% |
PD, 143 MND, 120 MS, 112 |
Yes | To examine differences in mood, symptoms, and QoL in people with progressive neurological illness, and to examine predictors of mood and QoL | QoL + | WHOQoL–BREFc | 60%, 13% |
| van Walsem (2017) [31] | Norway | Quantitative non-randomized—analytical cross-sectional design | mHDGECs, 84 | 57 | 56% | To describe HRQoL in mHDGECs and to examine the relationship of unmet needs for healthcare and social support services with HRQoL | HRQoL + | EQ-5Dc | 80%, 38% | ||
| Intervention studies | |||||||||||
| A'Campo (2012) [18] | NL | Quantitative non-randomized—single-group pre–post-design |
pHDGECs, 19 mHDGECs, 40 |
41 53 |
32% 65% |
Partners pHDGEC, 14 Carers mHDGEC, 28 |
No | To evaluate the feasibility of the Patient Education Program for HD (of which the goal is to improve QoL) | QoL– | SF-36c | 60%, 25% |
| Piira (2013) [27] | Norway | Quantitative non-randomized—single-group pre–post-design | mHDGECs, 37 | 52 | 49% | To evaluate the effects of a 1-year intensive, multidisciplinary rehabilitation program for mHDGECs (with HRQoL among the main outcome measures) | (HR)QoLm | SF-12c | 60%, 13% | ||
| Piira (2014) [28] | Norway | Quantitative non-randomized—single-group pre–post-design | mHDGECs, 10 | 50 | 50% | To evaluate the effects of a 2-year intensive, multidisciplinary rehabilitation program for mHDGECs (with HRQoL among the main outcome measures) | (HR)QoLm | SF-36c | 40%, 13% | ||
| Reyes (2015) [46] | Australia | Quantitative randomized-controlled trial—pilot study |
mHDGECs, 18 training (n = 9) control (n = 9) |
56 50 |
67% 56% |
To evaluate the effects of a 4-month respiratory muscle training on pulmonary and swallowing function in mHDGECs (with QoL among the main outcome measures) | Swallow QoL + | Swal-QoLc | 80%, 13% | ||
| Ringqvist (2021) [47] | Sweden | Quantitative non-randomized—cohort study | mHDGECs, 20 | 52 | 20% | To assess the effect and tolerability of a 25-day multimodal rehabilitation program for mHDGECs on psychiatric symptoms, HRQoL, and psychological health factors | HRQoL + | EQ-5Dc | 100%, 13% | ||
Mean and percentages in table are rounded
HD Huntington’s disease, N sample size (refers to participants with complete (HR)QoL data. In case of intervention studies, the N refers to the number of participants with complete (HR)QoL data at baseline), (HR)QoL (health-related) quality of life, MMAT mixed-methods appraisal tool, UK United Kingdom, NS not specified, CF cystic fibrosis, rLTND rare long-term neurological conditions, USA United States of America, pHDGECs premanifest Huntington’s disease gene expansion carriers, mHDGECs manifest Huntington’s disease gene expansion carriers, EQ-5D EuroQoL 5D, NR not reported, SF-36 Medical Outcomes Study 36-Item Short Form Health Survey, H-QoL-I Huntington Quality of Life Instrument, NL the Netherlands, WHOQoL-BREF World Health Organization Quality of Life Questionnaire short version, PD Parkinson’s disease, MND motor neuron disease, MS multiple sclerosis, ATC Assistive Technology for Cognition, WHODAS WHO Disability Assessment Schedule, Patient-Reported Outcomes Measurement Information System, EU European, HDQLIFE Huntington Disease Quality of Life, SF-12 Medical Outcomes Study 12-Item Short Form Health Survey, QoLI Quality of Life Inventory, RCT randomized-controlled trial
aIn case country of study/recruitment is not reported, country is based on author(s) affiliations
bStudy sample not clearly reported; decisions were based on reported characteristics of the study sample. In case of reported disease onset/duration, we grouped participants as mHDGECs. NS refers to articles that did not include sufficient information on the study sample (i.e., “HD gene-positive individuals” for Chapman 2002 and “HD patients” for McCabe 2009a)
cGeneric (HR)QoL instrument
dThe study also included pHDGECs but not as a sub-identifiable group as pHDGECs were grouped together with persons at risk
eStudy also reports relevant findings (e.g., evaluation of (HR)QoL or associated factors thereof) although this was not reported as part of the initial aim
fGroup A: pHDGECs furthest from predicted age of HD onset (n = 61); Group B: pHDGECs closest to predicted age of HD onset (n = 57)
gGroup C: mHDGECs in early stage I of the disease (n = 75); Group D: mHDGECs in early stage II of the disease (n = 42)
hDisease-specific (HR)QoL instrument
iMedian age for combined sample of pHDGECs and mHDGECs
jValue reported for combined sample of pHDGECs and mHDGECs
kAge range (30–84 years) was reported
lThe authors used others methods of data collection (i.e., interviews with family members and nurses, and qualitative observations of interaction between patients and nurses together), however only the results of the qualitative interviews with patients are reported as the data collection methods are not in accordance with our inclusion criteria)
mQOL and HRQOL was not used among the aim, but was used interchangeably in the main outcome measure section of the abstract and methods
+Intended construct of (HR)QoL corresponds with actual labeling of the tool
−Intended construct of (HR)QoL does not correspond with actual labeling of the tool
+ −Intended construct of (HR)QoL corresponds to some of the labels of the included tools